Another victory for the surging Toronto Maple Leafs carried with it a potentially large cost.

Auston Matthews, Leo Komarov and Matt Martin each scored in a nine-minute span in the second period and the Leafs rallied to beat the Buffalo Sabres 4-3 on Tuesday night for their 10th win in 13 games.

It wasn't all rosy for Toronto, though. Top defenseman Morgan Rielly left after the first period with a lower-body injury, and there was no update on the severity of the injury.

"He's a key part of our team," said James van Riemsdyk, who scored his 16th goal of the season. "You can see how minutes he plays and all the situations he plays in. Hopefully we get some good news on him."

The 22-year-old Rielly was carrying the puck out from behind his own goal when his right leg got locked with Carrier's right leg. Rielly's leg pulled in an awkward direction as it hit the ice, and he struggled to get to the bench before hobbling down the tunnel.

He returned for one shift, but then exited again, this time for good.

His absence, for any length of time, would leave a major hole in Toronto's lineup.

Rielly leads the Leafs in ice time, averaging almost 23 minutes per game alongside rookie Nikita Zaitsev. He's tasked with the most difficult minutes for coach Mike Babcock, matched nightly against opposing top lines while playing on both the power play and penalty kill.

Babcock said the team would know more on Rielly's status on Wednesday.

"He's a huge factor," Babcock said. "We've had lots of success this year with no injuries."

Toronto came back after trailing 2-0 through 20 minutes, getting its first victory this season when behind after one period (1-8-1).

Frederik Andersen made 24 saves for Toronto, and James van Riemsdyk also scored.

Kyle Okposo, Evander Kane and William Carrier each scored for Buffalo. Robin Lehner and Anders Nilsson allowed four goals combined on 32 shots.

The first period got off to an ominous start for the Leafs.

First was the injury to Rielly.

The Sabres struck first on Okposo's 13th this season shortly after the injury. The Buffalo winger scored promptly off a misplay by Andersen. Babcock challenged the play for interference on Carrier, who got tangled up with Andersen, but the goal was confirmed on video review.

Kane upped the Buffalo lead to two with 33 seconds left in the first, the 25-year-old beating Andersen on a one-time feed from captain Brian Gionta.

Komarov then scored 32 seconds into the second when Nazem Kadri's shot from the sideboards banged off the Finnish winger charging hard to the Buffalo goal. Martin tied it about eight minutes later when he threw a harmless shot from the corner at Lehner, the puck just sneaking through as the goalie hopelessly tried to pull it back.

Matthews put Toronto in front 47 seconds later with his team-leading 22nd goal of the year. Hard work behind the goal from linemates Connor Brown and Zach Hyman got the play going, with Hyman scooping up a loose puck and feeding Matthews in front. He whipped a laser just under the crossbar for his 16th goal in 23 games since Nov. 23.

The 19-year-old trails only Sidney Crosby and Jeff Carter in goals this season.

A frustrated Lehner was then pulled for Nilsson. As he approached the bench, Lehner looked in the direction of coach Dan Bylsma and appeared to say something. He then slammed the door to the bench and threw his mask down in disgust.

"He should be upset with getting pulled and that's part of Robin's game, that emotion," Bylsma said. "I have no problem with that."

Van Riemsdyk pushed the Leafs lead to two with his 16th goal of the year on a power play. The 27-year-old is riding an eight-game point streak, posting three goals and 12 points in that span.

Carrier pulled Buffalo back within one when he batted Zemgus Girgensons' pass out of midair to beat Andersen.

NOTES: The Leafs have won the first two meetings of five between Toronto and Buffalo this season.


Sabres: Host Detroit on Friday night.

Maple Leafs: Welcome the New York Rangers for a game on Thursday night.