Pascal Dupuis scored two of Pittsburgh's three goals in the third, and the Penguins stormed back to beat the Maple Leafs 3-1 on Thursday night and win their seventh game in a row.
Before the game turned dramatically, the Penguins were generating little offense against Toronto's tight checking, and goalie Ben Scrivens handled whatever chances got through to him.
But defensive zone breakdowns led to Dupuis' goals on setups from linemates Chris Kunitz and Sidney Crosby that sent the Maple Leafs to their fourth straight loss.
"We had our chances," Toronto coach Randy Carlyle said. "It's not all doom and gloom, but it's doom and gloom when you lose the way we lost. It tears at the fabric of your heart because we're finding a way to lose a game instead of finding a way to win a game."
Marc-Andre Fleury made 28 saves for Pittsburgh (20-8), which defeated the Maple Leafs 5-4 in a shootout in Toronto five days earlier.
Craig Adams sealed this win by scoring into an empty net with 10 seconds left.
"We didn't make it easy on ourselves," Crosby said. "We didn't execute, especially in the first two periods. But we kept it simple in the third and just tried to give us a chance to get back into the game. We were fortunate to do that."
Tyler Bozak had the lone goal for Toronto (15-12-1). Scrivens finished with 25 saves.
"It was a pretty choppy game from our standpoint," Penguins coach Dan Bylsma said. "But we didn't give up a lot. It was a tight game the whole way through."
Tied 1-1 in the third, Kunitz fed Dupuis in the slot for a shot that beat Scrivens and found the top corner with 2:10 left in regulation.
Pittsburgh trailed 1-0 after two periods but tied it when Kunitz won a puck battle in the Toronto zone and found Crosby. The Penguins captain then fired a backhanded, no-look pass to Dupuis, who beat a helpless Scrivens at 12:42.
"We know what type of player (Crosby) is for sure," Carlyle said. "He's a talented player. There's no secret that he's probably the best player in the league right now.
"He had a chance to make the difference and he makes the big play to Dupuis."
Maple Leafs center Leo Komarov had a breakaway with just over three minutes to go, after the stick of Penguins defenseman Brooks Orpik shattered, but Fleury made the save to keep the game tied.
"(Fleury) made some big saves throughout the game," said Crosby, who had two assists to give him 40 points in 26 career games against Toronto. "We made it difficult on ourselves and difficult on him.
"It's a lot different outcome if he doesn't play the way he does. That's a big plus for us, and we're lucky that he played the way he did."
Scrivens started ahead of James Reimer for Toronto, which had given up 18 goals over its previous four games (1-2-1).
"Fundamentally we had some breakdowns that cost us the hockey game," Carlye said. "I thought that for 53 minutes of the game we did a lot of things really well.
"(We) made some mistakes that cost us at a critical point in the game and they score two goals that were definitely flaws of defensive zone coverage."
Bozak opened the scoring at 10:01 of the second period. Phil Kessel brought the puck into the Penguins zone and delayed for a second before finding a pinching Cody Franson, who fed a pass to the wide-open Bozak at the side of the net for his seventh goal.
A sleepy first period featuring just 15 shots was in stark contrast to Saturday night's shootout between the teams.
"I like the standpoint that we didn't go off the page," Bylsma said. "We stayed with it and kept and at it. We didn't give up a lot, kept with this game, and ended up getting two points from sticking with it and playing the right way."