It was a heartbreaking upset for the Philadelphia Eagles who got defeated by the San Franciscso 49ers on Sunday's game with a 26-21 victory.

The game highlighted that the Eagles not only had poor offense but also lacked the effort to strengthen their defense. USA Today said that aside from the Eagles' poor performance as a team, quarterback Nick Foles also proved to be the "worst passer" of the game.

The team has also lost a number of credible players who were expected to really make a difference in their games which included Jason Kelce, who is suffering from sports hernia, injured Evan Mathis and Lane Johnson, who is serving a four-game suspension for violation of the NFL's performance-enhancing drug policy.

Eagles' coach Chip Kelly even said that his team "just got whooped up front."

"We're not very good up front right now. We've got a lot of guys banged up, and that's not an excuse, it's just the reality of it," he told USA Today.

The 49ers reportedly prepared well for their matchup against the Eagles and their grueling practice indeed paid off with their Sunday win. USA Today said that 49er defensive end Justin Smith was able to do what Foles failed to perform: play strong zone defense.

Kelly noted that Foles is "tough to grade" especially because the player has been pressured to be his best in every game.

"We've got to improve if people are just going to rush more. Maybe I'll do a better job at picking them apart in zones, and doing some of those things. I don't think anyone offensively did very well," Kelly added.

The coach is hoping that with the return of Johnson this week, the team will be able to improve its performance. USA Today said that Kelce, on the other hand, will miss two more months for his treatment while Mathis' recovery period is still unclear.

The 49ers, for their part, tried their best to go past the Eagles during Sunday's game with NFL.com, noting that the team was "oozing with talent, heart and character."

NFL.com observed that the 49ers' defense was so strong that Kelly's "high-powered" offense did not penetrate them. If the team wants to continue winning games, then Colin Kaepernick should improve his play, the report added.

On Sunday, Kaepernick made very few great moments which was limited to picking up a key first down which led to a scoring drive durin the first quarter, NFL.com continued. But his less accurate performance was highlighted more with him causing his team some vital points.

A similar Yahoo Sports report said Kaepernick's development as a player is important for the 49ers if they want to beat the reigning champions, the Seattle Seahawks, in the NFC West so he better balance his creativity and skills in their coming games.