"We put ourselves in a situation where those five games in December are meaningful," Kelly said.
It's a situation that looked unlikely three weeks earlier, when the team had lost its second consecutive game and the offense failed to score a touchdown during that span.
For the last three weeks, the Eagles have played close to complete football. Sunday's win marked the third consecutive game that the offense has scored at least three touchdowns and the defense has allowed fewer than three touchdowns.
"Offense, defense, special teams, we're all playing as one," running back LeSean McCoy said. "Sometimes early in the year, the offense was playing good, the defense wasn't. The defense was playing good, the offense wasn't. We're clicking [now]."
McCoy topped 1,000 rushing yards for the season with a 77-yard, two-touchdown performance. Nick Foles threw for 298 yards and rushed for 47 yards and a score. He is now 4-1 as a starter and still has not thrown an interception this season.
The triumphant locker room was only possible because the Eagles narrowly held onto a game that never should have been so close. The Eagles entered the fourth quarter with a 24-0 lead, but allowed two touchdowns and two two-point conversions to make it a one-possession game.
When the offense had a chance to salt away the game, they instead surrendered the ball with a three-and-out. A 70-yard punt pushed Washington back to its own 4-yard line with 3:26 remaining in the game.
An Eagles defense that had been stout for most of the game was tested. Washington drove 78 yards to create third and 1 from the Eagles' 18-yard line. Redskins quarterback Robert Griffin III was pressured by Fletcher Cox and underthrew a heave intended to go out of the end zone.
Brandon Boykin saw the ball floating in the air. "Is this real life?" Boykin said he thought to himself. He grabbed the interception to seal the Eagles victory with their second takeaway of the game.
"We had to make a play or they were going to make a play," defensive coordinator Bill Davis said. "And we stepped up and made it."
The Eagles built their lead in the first half. The first score came after LeSean McCoy took a wheel route for 49 yards to Washington's 4-yard line, and Foles rushed the ball into end zone two plays later.
On the Eagles' next drive, Brent Celek brought a screen pass 42 yards to the goal line. McCoy scored from 1 yard out on the next play to give the Eagles a 14-0 lead.
Washington then threatened to score and drove to the Eagles' 5-yard line. Connor Barwin sacked Griffin to knock the ball loose. Cox recovered the fumble, marking the second consecutive week that the Eagles forced a turnover in the red zone.
Alex Henery connected on a 24-yard field goal after the turnover to give the Eagles a 17-0 lead into halftime.
The Eagles opened the second half with a 13-play, 80-yard drive that finished with McCoy's 1-yard run. But the offense stagnated thereafter, and the defense's shutout was lost when they allowed two long fourth-quarter touchdowns.
The fourth-quarter problems will be overshadowed by the way the Eagles played most of the game. And that's also the way they've played most of the last three weeks. Players have remained confident, even when the Eagles sputtered to a 1-3 start with a struggling defense and languished at 3-5 with a dormant offense.
"You get to look in a man's eye and you can see if he's defeated or not," Foles said. "There's not one person on this team who was defeated. Everybody believed we could win."
Kelly said he has witnessed improvement. That has allowed the Eagles to enter the bye week atop the division. When they return, five meaningful games await. Even though Kelly said the team will pick its head up after the Dec. 29 finale against the Dallas Cowboys, the Eagles at least promised an intriguing final month.
"It's all for naught if we don't continue to build from here," Kelly said. "They understand that, too."