The suddenly surging Philadelphia Flyers are playing so well right now, coach Peter Laviolette is starting to expect it.

Former Maple Leafs enforcer Jay Rosehill scored the winning goal in his first game with Philadelphia, and Ilya Bryzgalov made 25 saves for the Flyers, who beat the Toronto Maple Leafs 5-3 on Thursday night for their fourth straight victory.

Simon Gagne, Jakub Voracek, Brayden Schenn and Luke Schenn also scored for Philadelphia (17-17-3), which is trying to make a late run for a playoff spot. Sean Couturier added two assists.

The Flyers are in 11th place in the Eastern Conference, but are only two points behind the eighth-place postseason cutoff.

"I really like the way we're playing right now. You could just tell that we were going to go out there and work hard," Laviolette said. "The new guys that came into the lineup were terrific in that regard."

Nikolai Kulemin, John-Michael Liles and James van Riemsdyk had goals for Toronto (20-13-4), which lost left wing Joffrey Lupul in the first period to an upper-body injury after he took a hard hit.

James Reimer made 26 saves for the Maple Leafs, but took his fifth regulation loss of the season one day after Toronto management decided against bringing in a veteran goalie at the NHL trade deadline.

Dion Phaneuf had two assists.

Lupul's status is now the biggest question mark surrounding the club as the Maple Leafs push for their first playoff berth since 2004.

Lupul, who assisted on Toronto's first goal, has 14 points since returning from a 25-game absence because of a broken forearm. He appeared to take a blow to the head in the first period after being sandwiched by Rosehill and Adam Hall, who also made his debut with the Flyers.

Lupul got back to his feet after the hit as play continued, but he was wobbly and had to be helped onto the bench. He left for the locker room a short time later and didn't return.

"You always take those situations with caution, and he feels fine now, but that's what happens in the context of the game," said Maple Leafs coach Randy Carlyle, whose team had a three-game winning streak and an eight-game point streak (5-0-3) snapped. "We'll have a much better read (on Friday)."

Brayden Schenn gave the Flyers a 3-2 lead just 54 seconds into the second period after a giveaway by Kulemin in the Toronto zone. Schenn moved into the high slot and fired a shot that squeaked through Reimer.

"I got most of it, just not enough," Reimer said. "You'd like to make a big save there, but it wasn't in the books."

The Flyers carried the play for the next few minutes, and the Maple Leafs responded with a couple of spirited shifts that got the crowd involved, including a pair of hits from Nazem Kadri.

But Philadelphia stretched its lead to 4-2 at 15:53 when Couturier's shot from the point was tipped in by Rosehill, who was acquired from the Anaheim Ducks on Monday. Reimer complained to the officials that he was interfered with, and replays suggested he had a case, but the goal stood.

"I was just trying to come in here and make an impact and have a good start to being in this organization," Rosehill said. "I'm pretty happy with the way it went. A big win."

Van Riemsdyk brought the Leafs closer at 6:14 of the third with his first goal in 11 games, roofing a shot from in tight on Bryzgalov for his 15th of the season.

Toronto had other chances to tie the game as the period wore on, including a big push in the final minute, but couldn't get even before Luke Schenn scored into an empty net.

"We didn't play desperate enough. We didn't execute to a high enough level. We were a step behind," said Carlyle of the Maple Leafs, who dropped to sixth in the East behind idle Ottawa. "Our execution was extremely poor."

Gagne opened the scoring on a nice deflection past Reimer just 1:19 into a physical first period. Kulemin tied it at 3:22, banging a loose puck past Bryzgalov.

After the hit on Lupul, Rosehill fought Toronto tough guy Colton Orr on his next shift.

Toronto went ahead at 16:46 on a shot from the point from Liles that found its way past Bryzgalov, who was screened by Frazer McClaren.

That lead was short-lived. Couturier sent a great pass to Voracek, who swept the puck past a helpless Reimer for his 16th goal.

"Shift after shift, nobody wants to let each other down with the work ethic right now," Laviolette said of the Flyers, who beat Montreal on Wednesday night. "It was a good win. It was a good win on the back-to-back."

NOTES: The Flyers acquired former Calder Trophy winning goalie Steve Mason from the Columbus Blue Jackets before Wednesday's trade deadline for backup goalie Michael Leighton and a third-round pick in the 2015 draft. Mason wore No. 35 for Philadelphia. ... Bryzgalov has played in 35 of 37 games this season. ... Maple Leafs defenseman Ryan O'Byrne, acquired from the Colorado Avalanche on Wednesday, arrived in time for the pregame warmup but didn't play.