Kim O'Reilly, CBS Sports

With less than a week left in the NBA regular season, there are still spots up for grabs everywhere you look in the standings. We know who the 20 postseason teams will be, but other than that very little is set in stone. The Play-In always creates a frenzy for the bottom half of the playoff bracket, but what's unfolding for the No. 1 seed in the Western Conference and the Nos. 2-6 seeds in the East will surely keep us entertained for the final handful of games.

It's only fitting that the Boston Celtics -- who clinched their top seed what seems like months ago -- would reassume the No. 1 spot in the Power Rankings as things draw to a close. They're an all-time great regular-season team with a chance to win 66 games -- something that's happened fewer than 20 times in NBA history.

But the big news this week isn't the old mainstay, it's the looming powerhouse surging up the rankings. Joel Embiid came back to fuel the 76ers to a 4-0 week, and a corresponding seven-spot jump. Philly is suddenly looking like one of the most threatening lower seeds in playoff history, especially with the flux that's occurring at the top of the East behind Boston -- five teams within 2.5 games of each other.

One of those teams, the Milwaukee Bucks, have seemingly forgotten how to win basketball games at the worst possible time. The No. 2 seed looked like a lock as recently as last week, but four straight losses have opened up the door for the Magic, Knicks, Cavs and Pacers. The week's biggest fallers, the Bucks need to figure it out -- and quick -- with the postseason right around the corner.

As we enter the final week of the regular season, here are the latest NBA Power Rankings.

*Please keep in mind that our NBA Power Rankings are based on weekly performance (Tuesday to Monday), not the whole season.

Biggest Movers
7 76ers
9 Bucks
1 Celtics The Celtics are so good that they're basically treating games as live practice reps while sitting a couple of their key guys every night -- and they're still winning. They beat the Thunder, Kings and Blazers this week with Jaylen Brown, Jayson Tatum and Kristaps Porzingis all averaging 20 points or more. They lead the East by a whopping 14.5 games. 1 64-18
2 Timberwolves The Wolves keep powering along without Karl-Anthony Towns (who may be back before the playoffs), racking up three more wins this week behind a sterling sub-100 defensive rating -- what else is new? They're currently sitting in first place in the Western Conference, with a massive matchup with the Nuggets set for Wednesday. Get your popcorn ready. 1 56-26
3 Nuggets Nuggets fans were relieved to see Jamal Murray take the court for Saturday's win over the Hawks after a seven-game absence due to a knee injury. The dynamic guard had three turnovers, but was efficient from the field, finishing with 16 points and six assists. He was plus-14 in 21 minutes. 1 57-25
4 Thunder OKC had a tough road to navigate this week without Shai Gilgeous-Alexander and Jalen Williams, coming out with a 1-3 record. They remain firmly in the mix for the No. 1 seed, and the injuries have led to reps for players they're going to need in the postseason like Aaron Wiggins, Isaiah Joe and Kenrich Williams. Running the show in SGA's absence, Josh Giddey averaged 15 points, eight rebounds and eight assists for the week. 3 57-25
5 Mavericks The Mavs are the hottest team in the NBA, and they continued their assault with a miraculous comeback to force overtime against the Rockets before eliminating them from the postseason. Kyrie Irving and Luka Doncic each averaged over 30 points this week, as Dallas is now 22-8 in its last 30 games -- second only to the Celtics over that span. -- 50-32
6 Clippers Kawhi Leonard's injury situation is troubling, but the Clippers have done an excellent job turning things around without him recently. They won three games this week, including a 26-point comeback against the Cavs on Sunday, and have now won six of their last seven to recapture a hold on the No. 4 seed. Paul George averaged 25 points for the week and was the hero in the big win over Cleveland. -- 51-31
7 Suns The Suns lost a big matchup with the Pelicans on Sunday, but are still playing good basketball over the last few weeks, winners of eight of their last 12 games. Frank Vogel must be ecstatic about his team's 101.3 defensive rating over the past week, which included wins over the Cavs and Wolves, as they'll need to flex their muscles on that end once the postseason begins. 1 49-33
8 Magic The Magic had a slight blip on the radar with a loss to the Hornets, but they've still won four of their last five as they draw ever closer to the No. 2 seed in the East while Milwaukee implodes. Paolo Banchero took the lead offensively this week, averaging 29 points and six assists, and they'll hope that Franz Wagner's ankle injury isn't serious enough to force him out for a significant period. 2 47-35
9 Knicks The Knicks received the devastating news that Julius Randle won't be back this season, but OG Anunoby did make his return this week, averaging eight points and three steals in two games. You'll be shocked to hear that, despite rusty shooting, he was a plus-12 in his 67 minutes. Jalen Brunson just keeps doing his thing, averaging 33 points and 10 assists for the week, including 43 in Sunday's win over the Bucks which brought them within a single game of the East's No. 2 seed. 2 50-32
10 Pelicans After losses to the Magic and Spurs to start the week, the Pelicans picked up a huge win over Phoenix on Sunday to draw even with them in the standings (though the Suns own the tiebreaker). Willie Green said the Pelicans are "hopeful" that Brandon Ingram can return before the end of the regular season, and they've gone 4-5 without him since his knee injury in late March. 1 49-33
11 Lakers The Lakers saw their four-game winning streak snapped in Sunday's loss to the Timberwolves (with LeBron James on the sideline), but they still have an outside shot to move out of the Play-In with a strong final week and some help from those ahead of them. They could also drop to 10th, however, and Tuesday's matchup with the Warriors will go a long way in determining that. 2 47-35
12 76ers Joel Embiid is back ... Tyrese Maxey dropped a career-high 52 points in Sunday's double-overtime win over the Spurs ... They've won five games in a row. Spirits are high right now with the 76ers. Beating the Spurs without Embiid gave a significant boost to the Sixers' efforts to get out of the Play-In. By the way, the big man hasn't missed a beat, averaging 28 points, seven rebounds and four assists in 28 minutes per game since his return. 7 47-35
13 Warriors It would have been nice if a close loss in Dallas went their way, but the Warriors continued their hot stretch this week to clinch a postseason berth. They've now won seven of their last eight games and have a chance to move out of 10th with big matchups against the Lakers and Pelicans on the horizon. Jonathan Kuminga returned from an extended absence on Sunday to put up 21 points and 10 rebounds in a win over Utah. 2 46-36
14 Pacers Things were looking a little shaky after a loss to the Nets to start the week, but the Pacers bounced back to win their next two games, including Sunday's massive victory over the Heat. Indiana now has the inside track to the No. 6 seed (or higher), meaning they'll likely avoid the Play-In. Pascal Siakam averaged 22 points and seven rebounds for the week on 52% shooting. 2 47-35
15 Kings The Kings continue to fight despite injuries to Kevin Huerter and Malik Monk, as they battle for positioning at the bottom of the Western Conference playoff picture. Last year's Clutch Player of the Year, De'Aaron Fox, knows it's time for him to step up, and he averaged 27 points and five assists on 39% 3-point shooting in a 2-2 week. Davion Mitchell has filled in some of those vacant guard minutes, putting up 11 points and three assists per game this week on 44% 3-point shooting. 1 46-36
16 Bucks So this is, uh, worrisome? The Bucks lost all four games this week -- three of which came against the Wizards, Grizzlies and Raptors (oh my!). Milwaukee has dropped six of seven games and is in significant danger of falling not only out of the No. 2 spot, but possibly all the way down to No. 5 or 6 depending on how things shake out over the final week. After Sunday's loss to the Knicks, Doc Rivers said his team is "too talented to go through this," and doesn't seem to have any answers. 9 49-33
17 Cavaliers The West Coast swing was not kind to the Cavs, as they lost four of five games capped by a 26-point blown lead against the Clippers on Sunday. With the way they're playing lately, they could realistically drop to sixth in the East. Donovan Mitchell only played in two of the four games this week, and he still doesn't look like himself as the postseason rapidly approaches. 1 48-34
18 Heat The Heat dropped a massive game to the Pacers on Sunday, increasing the likelihood that they'll end up in the Play-In Tournament. The good news is that Tyler Herro returned to the lineup this week after being out since the end of February, averaging 19 points, five rebounds and four assists on 50% shooting in two games. 1 46-36
19 Rockets Five losses in a row officially eliminated the Rockets from postseason contention, but they can be proud of the meaningful steps the franchise has taken this season. Jalen Green cooled off this week but, along with Alperen Sengun, Jabari Smith Jr., Amen Thompson and Cam Whitmore, he gives Houston fans plenty to be excited about moving forward. 1 41-41
20 Bulls The Bulls split their two games this week and hold onto the No. 9 seed over Atlanta by the slimmest of margins. Chicago signed familiar face Javonte Green to a 10-day contract and he immediately delivered, averaging 20 points, 10.5 rebounds and two blocks against New York and Orlando. 1 39-43
21 Hawks For a hot second it looked like Atlanta might catch Chicago for the right to host the East's 9-10 matchup, but losses to the Mavs and Nuggets to end the week dampened that excitement. It's still possible, of course, and the Hawks being above .500 without Trae Young this season has to be considered a win. 1 36-46
22 Nets Brooklyn picked up wins over the Pacers and Pistons to start the week, then ran out of gas and only generated 77 points in Sunday's loss to the Kings. Rookie Noah Clowney has been a pleasant surprise in some newfound rotation minutes, averaging 15 points, nine rebounds and two blocks in 25 minutes per game this week. -- 32-50
23 Grizzlies Given the number of injuries on their roster, it's simply remarkable that the Grizzlies have been able to win some games recently -- including an absolute stunner in Milwaukee on Wednesday in which Jaren Jackson Jr. went off for 35 points. Things didn't go as well against the 76ers on Saturday with players like Maozinha Pereira, Zavier Simpson and Timmy Allen getting major minutes. 2 27-55
24 Raptors Toronto finally snapped its 15-game losing streak in the most implausible of ways, beating the Bucks on their home floor behind 31 points from Gary Trent Jr. Once they got a taste of winning, they just couldn't stop, beating the Wizards on Sunday to make it two in a row. It certainly helps to have Immanuel Quickley and RJ Barrett back in the lineup, as the duo combined to score over 48 points per game this week. 6 25-57
25 Trail Blazers Despite multiple key absences, the Blazers managed to win games this week against the Hornets and Wizards before returning to reality in Boston. Deandre Ayton actually played all three games this week (gasp), averaging 27 points and 14 rebounds on 51% shooting. 4 21-61
26 Spurs In this week's edition of "What kind of nonsense has Victor Wembanyama gotten up to this time?" the Rookie of the Year-to-be nearly put up a QUADRUPLE-DOUBLE (23 points, 15 rebounds, nine blocks, eight assists) against arguably the best player in the world in Nikola Jokic. Wembanyama then led San Antonio to a win over the Pelicans before falling short in double-overtime against the 76ers on Sunday. He also shot 37% from 3-point range in the three games. What else can you say? 3 22-60
27 Hornets The Hornets can be happy with the way they played this week, beating the Magic while suffering close losses to the Blazers and Thunder. Grant Williams morphed into a starting point-center due to injuries, averaging 14 points, eight assists and five rebounds on 52/67/86 shooting splits in the three games. 1 21-61
28 Wizards The Wizards have lost six of their last seven games, but the one win -- over the relatively healthy Bucks -- was certainly one to write home about. Jordan Poole and Deni Avdija are both closing the season strong, combining to average nearly 45 points, 13 assists and 12 rebounds this week. -- 15-67
29 Jazz Now that the Raptors have snapped their skid, the Jazz are the owners of the league's longest losing streak at 12 games. I'll give you a crisp $1 bill if you can guess who Utah's leading scorer was this week. What, no takers? UCLA's own Johnny Juzang at 18 points per game -- on 9-for-13 3-point shooting, no less. 5 31-51
30 Pistons In case you missed it, fourth-year guard Malachi Flynn dropped the most unexpected 50-burger in NBA history. No, really. No player with a lower career scoring average had ever scored 50 points in a game -- and he did it off the bench. The mighty fall quickly, however, as Flynn went just 1 for 19 with six total points in his next two games. 3 14-68