The Toronto Maple Leafs avoided another late-game collapse Saturday night at the Air Canada Centre, surviving an energetic performance by the Calgary Flames.

Captain Mats Sundin netted a hat trick, including his 500th career goal, to lift the Leafs to a thrilling 5-4 overtime victory over the Flames.

With the Flames on the power play, Sundin outmuscled Alex Tanguay at the Leafs blue-line, raced up ice and unleashed a slapshot that sailed over the shoulder of goaltender Miikka Kiprusoff just 50 seconds into overtime.

The goal was Sundin's fourth point of the night, as the captain led a Toronto comeback that began late in the second period.

"Certainly, I'm proud of the accomplishment, and it makes it special the way it happened, to get the win in overtime, too," said Sundin.

The winhelped erase memories of a bitter defeat Toronto incurred against the New Jersey Devils on Thursday night. The Leafs built a three-goal lead after 40 minutes before letting New Jersey back into the game and eventually losing in a shootout.

"More than anything, it's nice to get it over with," Sundin said of the milestone goal. "I didn't want it to go 15 or 20 games into the season and still be looking for it."

Forward Darcy Tucker scored his fifth goal of the season and added an assist, while Alex Steen added the other Toronto tally.

Despite the loss, the game was especially memorable for Calgary defenceman Mark Giordano.

The Toronto native scored two goals, including a pretty play that gave Calgary its only lead early in the second period.

"It's tough to get tickets here, but I tried to accommodate as many people as I could," Giordano said. "I had about 10 people here, mostly relatives. I'm sure they were excited for me."

The Flames continued to struggle with their inept power play against the Leafs. Calgary failed to score on three opportunities Saturday night, bringing its woeful unit to 1-for-33, the worst in the league.

With the Leafs trailing 3-2 late in the second period, Steen evened the game at 17:38.

After the initial shot slid to the side of the post, Matt Stajan directed a pass to the crease that was directed in by Steen.

Toronto took its second lead of the game a minute later on Sundin's second goal of the game. The Toronto captain took a drop pass from Tucker and wristed a shot over the shoulder of Kiprusoff that changed direction off the stick of Giordano.

The Flames pulled even at 7:15 of the third after taking advantage of a Toronto turnover. Jarome Iginla stripped defenceman Hal Gill of the puck and fed a nifty pass to Daymond Langkow, who snapped a shot by Raycoft.

The goal, however, would allow Sundin to reach his milestone mark in overtime.

"It's only fitting that he score the overtime goal because he's scored so many huge goals for us," said Tucker.

"And it's great that he got that standing ovation from the fans."

The Leafs opened the scoring on the power play at 8:09 of the first period. With Toronto controlling the puck down low, Tucker took a cross-ice pass from Kyle Wellwood and buried a one-time past Kiprusoff.

Toronto increased its lead by two goals 7:17 later, just as the team's 5-on-3 advantage expired. Defenceman Bryan McCabe feathered a pass to Sundin, who snapped a shot over the out-of-position Kiprusoff.

Calgary cut Toronto's lead to 2-1 at 4:52 of the second on Giordano's first career NHL goal. Matthew Lombardi picked up a loose puck behind the Leaf net and fed a perfect pass to Giordano. The Flames defenceman made no mistake as beat Toronto goaltender Raycroft with a wrist shot to the stick side.

The Flames evened the game 2-2 more than three minutes later with a short-handed goal after catching Toronto on a line change. Lombardi stationed himself to the side of Raycroft and converted his second opportunity with a shot under the Leaf goaltender.

Giordano then scored his second career goal on a beautiful play at 11:26 of the second. With the Flames circling the Leaf zone, Giordano took a pass from Iginla, cut in front of the Toronto net and slid a backhand shot behind Raycroft.