Opposing quarterbacks don't usually just waltz into Lincoln Financial Field — especially when playing as a division rival — and turn in the best performance of their career.

But Washington Redskins quarterback Kirk Cousins did just that on Sunday.

Cousins, playing for an injured Robert Griffin III, recorded his first start of the season on Sunday, setting career highs in completions (30), passing yards (427) and passing touchdowns (three) in the Redskins' 37-34 loss to the Philadelphia Eagles.

Cousins' 427 passing yards were the fourth-most by a Redskins quarterback in a regular-season game in team history, trailing only Brad Johnson (471), Mark Rypien (442) and Doug Williams (430).

Cousins was quick to credit those around him for his solid performance.

"As an offense, as a quarterback, you just have so many people around you who can make you successful," the Michigan State product said. "And that's what I think I take away from today is the good thing we have right now, and we obviously need to get better. But there's a lot there to work with."

Cousins' overall performance Sunday wouldn't have been possible without a hot start. The third-year quarterback

completed 12 of his first 13 passes, two of which he threw for touchdowns — one to fullback Darrel Young and the other to wide receiver Pierre Garçon — to give his team an early 14-7 lead.

In the process, Cousins became the first Redskins quarterback since Mark Brunell on Dec. 24, 2005, to throw for two touchdown passes in the first quarter of a regular-season game.

Redskins head coach Jay Gruden said he felt Cousins played "excellent" on Sunday.

"Overall, man, to throw for over 400 yards on the road, I think he did an excellent job with limited reps the whole camp," Gruden said. "I'm very proud of Kirk – the way he played and the way he battled."

Cousins, however, acknowledged that not every play went as planned Sunday vs. the Eagles.

Two plays in particular — a fourth-quarter interception and overthrowing a wide-open Garçon on fourth down on the Redskins' final drive of the game — sting more than the others, he said.

Cousins said he'll watch the film today to try to ensure his footwork is better Thursday night against the New York Giants at FedExField.

"I think accuracy goes back to your feet," he said. "You have to always be balanced. You have to always be consistent and then you can always be accurate. When that balance and that consistency starts to change then that's where the accuracy starts to waiver and that's where I have to go back and study my footwork and make sure that I'm keeping myself balanced."

Cousins on Sunday turned in his second-straight impressive performance in relief of Griffin III, who dislocated his ankle Week 2 against the Jacksonville Jaguars and is expected to miss at least six weeks, according to Gruden.

In his two games this season, Cousins has completed 52-of-81 passing attempts for 677 yards and five touchdowns to just one interception, turning in an overall quarterback rating of 105.8.

His teammates said the quarterback will only get better as he receives more first-team reps in practice.

"Kirk has been here since April, we all been here since the beginning of the offseason training program, so I've been catching a lot of balls from Kirk and he does a great job of staying tuned in," said wide receiver DeSean Jackson, who caught five passes for 117 yards — including an 81-yard touchdown — on Sunday against his former team. "Last week, he did a great job of replacing RG3, and he had a great game today."

Garçon — who caught a team-best 11 passes for 138 yards and a touchdown — said he hasn't been surprised by Cousins' performances the past two weeks.

"He's taking practice serious as if he is in the game and it shows," Garçon said. "He has a lot on his shoulders and he responds well."

Gruden — who was encouraged by the fact Cousins attempted 48 passes on Sunday and was not sacked once — said there's "a lot to be encouraged with" with Cousins under center for the Redskins.

"We're disappointed with this loss, but I think everybody can see that there is major improvement going on here," he said. "And everybody can rally around Kirk for the next six or seven weeks."

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