TORONTO -- Matt Carkner knew had to do something.
After Joffrey Lupul walked around the New York Islanders defenseman for the game's first goal, the Toronto Maple Leafs took an early 2-0 lead when Cody Franson scored with Carkner in the box serving an interference penalty.
Carkner dropped the gloves with Maple Leafs tough guy Frazer McLaren. Four seconds later, New York's Eric Boulton and Toronto's Colton Orr fought.
Those two fights changed the momentum in New York's favor, and the Islanders scored five unanswered goals en route to a 5-3 win Thursday night.
"The first two goals was all on me," Carkner said. "I had to do something for sure."
New York (23-16-5) improved to 16-2-1 when leading after two periods, and it now has points in nine straight (7-0-2). It's the Islanders' longest point streak since the start of the 2001-02 season, when they went 9-0-1.
John Tavares, who entered Thursday having failed to register a point in three straight games, scored first- and second-period goals to give the Islanders a 4-2 lead after 40 minutes.
"I really thought those two fights got us going," Tavares said. "Carks and Boult made big sacrifices for us there and kind of woke us up a bit.
"Any time you start like that, I think it's disappointing. We got our game back, and we got a goal that really helped as well.
"But I really thought those two guys got us going and gave us momentum. Then we started getting our legs going."
Tavares set up Brad Boyes near the midway mark of the first period, cutting Toronto's lead in half. Matt Moulson tied the game 2-2 six minutes later. Tavares then kept the puck on a 2-on-1 and beat Leafs goalie James Reimer to give the Islanders a 3-2 lead after 20 minutes.
Tavares made it 4-2 in the second when beat Reimer with a wrist shot glove-side off a Moulson feed.
The win moved New York within two points of Toronto for fifth place in the Eastern Conference.
New York's top line of Tavares, Boyes and Moulson combined for eight points.
Tavares, a native of Oakville, Ontario, now has eight goals in 15 career games against the Maple Leafs.
Frans Nielsen made it 5-2 slapping a Kyle Okposo feed past Reimer midway through the third.
Dion Phaneuf got the Leafs to within two in the final minute.
"We've been making the game harder on us than we usually do, and that's the biggest thing," Phaneuf said. "We, as a group, right through, know we've got more, and we've just been making uncharacteristic mistakes."
Toronto (24-15-5) could've clinched a playoff spot with a win Thursday and a Winnipeg Jets regulation loss. Neither happened, as the Jets defeated the Carolina Hurricanes 4-3 in overtime.
Thursday marked the first time the Leafs lost back-to-back games in regulation since March 12 and March 14. The defeat also snapped Toronto's three-game home win streak. The Leafs had won seven of eight at the Air Canada Centre coming in.
NOTES: Lupul's opening goal was also his 100th point as a member of the Leafs.
... New York looks poised to make the playoffs for the first time since 2007. ... The Leafs currently own the league's longest postseason drought, having last played a postseason game in 2004. ... Leafs forward Clarke MacArthur returned to the lineup after being a healthy scratch Tuesday in Washington. ... Toronto defenseman Carl Gunnarsson missed his third straight game with a lower-body injury. ... Casey Cizikas, who suffered an upper-body injury blocking a shot on Tuesday, was in the Islanders' lineup. ... Maple Leafs forward Phil Kessel played in the 500th game of his career. ... Jack Capuano moved into second place on the wins list in Islanders franchise history on Tuesday with his 82nd victory. Capuano trails only Al Arbour, who ranks first with 740 wins.