Clarke MacArthur's second goal of the game at 2:06 of overtime lifted Toronto over the New York Islanders 4-3, giving the Maple Leafs a sweep of the home-and-home series.
Toronto rallied from a 2-0 deficit to take a 3-2 lead late in the third period, only to have the Islanders tie it with 12.2 seconds left in regulation.
"We got it going in the last two periods and kept it going into overtime," MacArthur said. "We battled hard."
MacArthur took a feed from Mikhail Grabovski and slid the puck into goalie Al Montoya's glove, which was inside the net. Both teams waited on the ice for the official ruling that deemed it a goal.
It was MacArthur's 14th of the season and it sent the Maple Leafs (25-19-5) into the all-star break tied at 55 points for the last Eastern Conference playoff spot. New Jersey, Florida and Washington also have 55 points, but the Capitals are considered the Southeast Division leaders and are listed as third in the conference.
Toronto, which hasn't won the Stanley Cup since 1967, last reached the playoffs in 2004. The Leafs beat the Islanders 3-0 on Monday night.
"It's a good way to go into the break for us," Maple Leafs coach Ron Wilson said.
Toronto goalie Jonas Gustavsson made several sterling saves moments before the Maple Leafs rushed up ice, leading to the winning goal. Gustavsson stopped 29 shots in all.
"It was exciting, many chances back and forth," Gustavsson said. "I'm really happy Clarke scored in overtime and got us the two points."
P.A. Parenteau scored for New York with 12.2 seconds left in the third period to force overtime. His unassisted goal on a slap shot from between the faceoff circles was his 10th of the season.
Grabovski's fluttering shot with 3:31 remaining in the third put Toronto up 3-2. The puck knuckled over Montoya's right shoulder and into the net after it ricocheted off the stick of Islanders defenceman Milan Jurcina. Grabovski also had three assists.
"It was an odd game. It seemed like every goal was a bounce on their side," Montoya said.
It was the second straight game between the teams in which Toronto didn't have to kill off a penalty.
"I'm not one to comment on officiating," Islanders coach Jack Capuano said. "It is what it is."
Goals by John Tavares and Josh Bailey put New York ahead 2-0 before the Maple Leafs rallied for three straight goals.
Tavares — whose NHL season-high 12-game points streak ended a night earlier — scored his 20th of the season at 1:54 of the first period, knocking a rebound past Gustavsson.
Bailey's short-handed score at 9:17 of the second period, his fifth of the season, on a perfect pass from Matt Martin made it 2-0. The goal came with defenceman Travis Hamonic in the penalty box for holding Toronto's Phil Kessel.
Toronto broke up Montoya's shutout bid at 18:55 of the second when MacArthur scored.
Maple Leafs defenceman Jake Gardiner tied it 2-2 with his first NHL goal at 1:47 of the third. Montoya protested because MacArthur was at his feet in the crease — after being shoved by an Islanders defenceman — but the goal counted.
The game had its chippy moments. There were numerous post-whistle skirmishes at both ends of the ice. Tavares appeared to be elbowed in the face by Kessel behind the Islanders net at the second-period horn. No penalty was called.
Tavares yelled at the officials as he headed off the ice.
"I was pretty heated. It didn't make a whole lot of sense," Tavares said. "I thought he saw it."
The Maple Leafs have won five of their last six meetings with the Islanders and are 3-0-1 in their last four trips to Long Island.
Gustavsson made 25 saves Monday night for his third shutout in January as the Maple Leafs beat the Islanders in the home-and-home opener.
"These were two playoff-like games," Maple Leafs captain Dion Phaneuf said. "They played their game really well and we came back well. We played a pretty solid road game."
NOTES: The game was played on the 31st anniversary of Islanders star Mike Bossy becoming the second player (after Maurice Richard) in NHL history with 50 goals in 50 games when he scored twice with less than 5 minutes left in the third period against Quebec Nordiques goalie Ron Grahame ... Toronto has the second-youngest roster in the NHL behind Colorado with an average age of 26.6 years old. .... Both teams resume play after this weekend's All-Star game on the road, the Islanders at Carolina next Tuesday and Toronto at Pittsburgh the same night.