The Pittsburgh Penguins were generating little offence against Toronto's tight checking and goaltender Ben Scrivens was handling whatever chances did get through.
All that changed thanks to defensive zone breakdowns that led to two goals by Pascal Dupuis on setups from linemates Chris Kunitz and Sidney Crosby as Pittsburgh stunned Toronto 3-1 to send the Leafs to their fourth straight defeat.
"We had our chances ... it's not all doom and gloom but it's doom and gloom when you lose the way we lost," Carlyle said. "It tears at the fabric of your heart because we're finding a way to a lose a game instead of finding a way to win a game."
Pittsburgh trailed 1-0 after two periods but tied it at 12:42 of the third when Kunitz won a puck battle in the Toronto zone and found Crosby at the side of the net. The Penguins captain then fired a backhand no-look pass to Dupuis, who beat a helpless Scrivens.
"We know what type of player (Crosby) is for sure. He's a talented player. There's not secret that he's probably the best player in the league right now — that's fact," Carlyle said. "He had a chance to make the difference and he makes the big play to Dupuis."
Kunitz then fed Dupuis in the slot and he wired a shot past a screened Scrivens into the top corner with 2:10 left in regulation for the winner.
Toronto had a late power play, but Craig Adams scored into an empty net with 10 seconds left to ice things.
"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, and we were fortunate to do that."
The Maple Leafs had given up 17 goals in the previous four games and were solid in the defensive zone until that critical spell late Thursday.
"Fundamentally we had some breakdowns that cost us the hockey game," Carlye added. "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."
Marc-Andre Fleury made 28 saves for Pittsburgh (20-8-0), which defeated the Maple Leafs 5-4 in a dramatic shootout on the same ice five days earlier and has now won seven in a row.
Toronto centre Leo Komarov had a breakaway with the score tied in the third, but Fleury came up with the save to keep the teams level and set up Dupuis' winner.
"(Fleury) made some big saves throughout the game," said Crosby, who with two assists now has 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."
Tyler Bozak had the only goal for Toronto (15-12-1). Scrivens made 25 saves in taking the loss in front of 19,561 at Air Canada Centre.
"You never want to lose and it's even more disheartening at times when you lose because of errors late in the game. Hopefully we can learn from this one," Scrivens said. "We've got so many good things to take out of it. We just have to sharpen a select few small things and we'll be rolling."
Bozak opened the scoring in a game that desperately needed a goal at 10:01 of the second period. Phil Kessel brought the puck into the Penguins zone and delayed for a split second before finding a pinching Cody Franson, who in turn found a wide open Bozak at the side of Fleury's net.
"I thought we had a good game out there for the most part. It wasn't work ethic that was the problem," said Bozak. "I think a couple lapses obviously ... it's a tough loss. You always want to hold on when you're leading after two."
The game was missing a level of creativity that could have been provided by injured Penguins superstar Evengi Malkin, who missed his third straight game with an undisclosed injury. The Russian centreman, who was hurt in the previous outing against Toronto, has five goals and 19 assists in 21 games. He missed four games earlier this season with a concussion.
"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."
A sleepy first period featuring just 15 shots and uninspired play was in stark contrast to Saturday night's exciting shootout between the two teams. Kessel saw Fleury turn aside Toronto's best chance off the rush, while Crosby had a good opportunity in the dying seconds of the period, but his shot whistled just wide.
"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."
Notes: Both teams finished the night 0-for-3 on the power play. ... Leafs defenceman John-Michael Liles returned to the lineup after being a healthy scratch for the previous 12 games. ... The Leafs made a trade involving two players in the American Hockey League prior to the game, sending forward Nicholas Deschamps to the Washington Capitals for defenceman Kevin Marshall. ... With the NHL's realignment approved by the board of governors, Toronto will be in a division with Boston, Buffalo, Detroit, Florida, Montreal, Ottawa and Tampa Bay beginning next season. Pittsburgh will be lined up against Carolina, Columbus, New Jersey, the New York Islanders, the New York Rangers, Philadelphia and Washington.