Getty Images

PHILADELPHIA -- The San Francisco 49ers preached if their quarterback was healthy, they had a significantly better chance to beat the Philadelphia Eagles. Brock Purdy left with an injured elbow on the 49ers' sixth offensive play of the NFC Championship game, a 31-7 loss to the Eagles in a game which backup quarterback Josh Johnson was also knocked out. 

Purdy wasn't knocked out of this Week 13 rematch, throwing for 314 yards and four touchdowns. The 49ers won 42-19 over the team with the best record in the NFL.

Point proven? Trent Williams didn't mince words. 

"I guess it's up to y'all to kind of interpret it," Williams said after the game. "I had full confidence we would have this type of game from the jump. We got a quarterback, so it made it a lot easier this time." 

The 49ers have played four games against teams this season that entered multiple games over .500, winning each by 18-plus points. Their plus-104 point differential in those games is the highest by any team in their first four games against teams entering multiple games over .500 in NFL history, per CBS Sports Research. 

Purdy played in all those games, completing 70.5% of his passes for 1,140 yards with 10 touchdowns to three interceptions for a 121.9 passer rating. He averaged 10.2 yards per attempt in those games. 

Perhaps the 49ers are onto something. 

"We wanted some payback," 49ers pass rusher Nick Bosa said. "We tried not to think too much about last year, but we knew we could match up with them -- and more than that. I think we proved a good point."