"It was one of those games that was very chippy; everybody knew how big this game was," Lecavalier said.
It was a reversal of the Flyers' 5-4 shootout loss in Washington on Dec. 15, a game in which the visitors blew a 4-1 third-period lead.
The victory gave the Flyers key wins over the New York Rangers and the Capitals on consecutive days. They are now two points ahead of the Caps.
"It's going to be tight until the end of the season," said Jake Voracek, who got the Flyers to within 4-3 with a late power-play goal. He added: "I think we made a statement the last two games against teams like that, so that's a huge four points for us."
The Flyers notched their sixth win in seven games and moved into second place in the Metropolitan Division, one point ahead of the Rangers, who lost to Boston, 6-3, on Sunday night.
As for all the late comebacks, "that means we have to play the first and second periods better, right?" Flyers coach Craig Berube said, only half-jokingly. "First period wasn't good. I thought we were good after that. I liked the second period. I liked the third, obviously."
With Steve Masson pulled for an extra attacker, Claude Giroux (two goals, three points) tipped in Voracek's right-circle drive with 1:05 left in regulation to tie the score at 4-4.
The Flyers had gotten to within 4-3 when Voracek scored with 8:02 left during a five-minute power play, awarded because of Dmitry Orlov's boarding major against Brayden Schenn.
"We gave them life," Caps coach Adam Oates said.
After Voracek's goal, "we played the way we know how to play, that we have played in third-period pushes," Lecavalier said. "Just getting in deep."
Kimmo Timonen set up the game-winner and had three primary assists for the Flyers, who ended the Capitals' four-game winning streak.
Just 54 seconds after Adam Hall converted an Alex Ovechkin (minus-3) turnover into a shorthanded goal to tie the game at 2-2, the Capitals took the lead on Jay Beagle's second goal of the season.
Taking a slick backhanded pass from Joel Ward, Beagle scored from in close with 6:16 left in the second period.
Less than three minutes later, Orlov scored his second goal of the game, beating Steve Mason on a point drive with a maze of players in front of the goalie.
In the first two periods, the Flyers gave Washington five power plays. Technically, the Caps didn't score on any of them, but one of their goals was scored just as a penalty expired. The penalties also prevented the Flyers from getting into any type of flow.
The Flyers were fortunate to face just a 2-1 deficit after a Caps-dominated first period.
Washington nearly took a 3-1 lead with a little under five minutes left in the first period, but it was ruled that Nicklas Backstrom's shot did not cross the goal line after the puck hit Mason and trickled through him. Defenseman Mark Streit cleared the puck - most of it was over the goal line - and replay officials in Toronto ruled that there was inconclusive evidence that the entire puck was in.
The officials on the ice had ruled that it was not a goal.
"We never gave up and we stayed patient," Streit said of the comeback. "It shows how much character we have in the room."