Riding Kessel's three-goal performance, Toronto recovered from a poor start to defeat Anaheim 4-2 Tuesday night and deny the Ducks a club-record eighth straight win.
It was a Jekyll and Hyde performance for the Leafs, who were booed off the ice after a woeful first period that saw them outplayed, outshot 6-2 and outscored 1-0. Kessel struck twice and Toronto scored three unanswered goals in the second period to climb out of a 2-0 deficit.
"The first period we were awful tight," Toronto coach Randy Carlyle said. "We couldn't execute a 20-foot pass if the guy was wide open. ... We were tripping over one another the first period."
Toronto got its forecheck going and Kessel started the comeback with a power-play goal at 7:44 of the second period. The Ducks began to unwind and the Leafs led 3-2 going into the third.
Anaheim coach Bruce Boudreau was left lamenting the rapid turnaround.
"We played really good for the first 30 minutes of the game. I mean, as good as we can play," he said. "But I think the big thing is we just lost our composure for 10 minutes. And we've got to get it back. We'll get it back in practice (Wednesday)."
Captain Dion Phaneuf also scored for the Leafs.
James van Riemsdyk, who fed Kessel most of the night, had a chance to make it 5-2 in the third period, but hit the goalpost with a backhand on a penalty shot after being interfered with on a breakaway.
Kessel, whose offense has been sporadic this season, upped his goal total to five with the hat trick. The Leafs star came into the game with two goals on 36 shots. He left with five on 40.
Nick Bonino and Mathieu Perreault scored for Anaheim.
The win snapped a two-game losing streak for the Leafs and Carlyle, who led the Ducks to the Stanley Cup in 2007 before being fired in 2011.
Anaheim outshot Toronto 25-23.
Shots have been hard to come by for the Leafs, who were outshot 115-60 in their three previous games. Toronto has been outshot in eight of 10 games this season, including its last seven outings.
Neither team showed much in a loose first period that saw Toronto register its first shot 27 seconds in and then not put another on Jonas Hiller until an easy long-range shot from defenseman Paul Ranger with 2:56 left in the period.
Thirty-four seconds later, Bonino tapped in a pass from Patrick Maroon on a three-on-one after Leafs defenseman Cody Franson collided with teammate Troy Bodie up ice. It was Bonino's fourth of the year.
Carlyle's advice to his tense team after the first period was to relax and "go play."
Still stuck on two shots, Toronto went down 2-0 at 1:59 of the second period after Perreault was allowed to come out from behind the goal and roof a wrist shot past Jonathan Bernier for his fourth of the year.
The Leafs finally scored 7:44 into the second period with Kessel tucking in the puck on the power play after van Riemsdyk stretched to pass a rebound to his unmarked linemate for his third goal.
Phaneuf tied it at 9:03, cruising in from the blue-line to bang home a rebound for his second of the season.
The dazed Ducks called a timeout to regroup.
Toronto had to survive an 87-second five-on-three power play later in the period.
Kessel scored again after Ranger got a turnover and sent his winger off on a two-on-one with van Riemsdyk. Kessel held onto the puck and beat Hiller at 16:09 for a 3-2 lead and his fourth goal of the campaign.
The shot count was tied 12-12 after two periods with Bernier making some timely stops in the third.
Kessel made it 4-2 at 8:11 of the third, effortlessly converting a two-on-one with van Riemsdyk.
"JVR made two great passes to me and I was fortunate enough to bury both of them," said Kessel, who signed an eight-year, $64 million contract extension this month. "It was a good night."
It was the Ducks' first defeat since a season-opening 6-1 loss in Colorado. Anaheim arrived in Toronto on a seven-game win streak, tied for the longest in club history (set previously between Feb. 20 and March 7, 1999).
The loss dropped the Ducks' record at Air Canada Centre to 3-12-4 and Hiller's career mark against the Leafs to 0-4-0.
The last time the clubs met, a 5-2 Toronto win at the Honda Center on Nov. 27, 2011, Carlyle was behind the Ducks' bench. He was fired three days later and replaced by Boudreau.
NOTES: Tuesday's game was the first stop on a season-long eight-game, 15-day road trip for the Ducks. ... Steve Yzerman and Peter Chiarelli of the Canadian Olympic team brain trust attended the game. ... Anaheim continues its road trip on Thursday in Montreal and Friday in Ottawa. ... The Leafs will finally get forward David Clarkson back from his 10-game suspension on Friday in Columbus.