Sundin's second goal with 1:08 left in regulation forced overtime, and the Leafs went on to a 4-3 shootout victory over the Florida Panthers.
"He's the man here, and he's always been," said defenseman Tomas Kaberle, who scored the only goal of the shootout. "Everybody follows him and tries to play like him."
The rebuilding Maple Leafs hoped to convince Sundin, the longtime captain, to waive his no-trade clause before the NHL's dealing deadline on Tuesday. Sundin decided he'd rather stick around Toronto instead of being a hired gun.
For at least one night, it paid off for the Leafs.
Kaberle scored on Toronto's first attempt of the shootout when he slid the puck between Tomas Vokoun's legs on a deke.
Vesa Toskala sealed the victory when he blocked Olli Jokinen's wrist shot on the final attempt of the shootout. Toskala also stopped Rostislav Olesz, who hit the post on a deke attempt, and Ville Peltonen.
Toronto is six points below the postseason cutoff in the Eastern Conference.
"Six points is not much," Kaberle said. "We need to get on a roll. It's wide open if we keep winning."
Sundin, among five Toronto players who declined to waive no-trade clauses before Tuesday's deadline, had two goals and an assist.
Jeremy Williams had the other goal for the Leafs, who have won five of six.
Toskala made 37 saves in regulation and overtime. Vokoun stopped 34 shots.
Florida beat the Leafs 8-0 in the last meeting between the teams Feb. 5, the most lopsided victory in Panthers history.
Sundin tied the game after Toronto pulled Toskala, sending a wrist shot from the high slot between Florida forward David Booth's legs and past Vokoun to the glove side.
"He probably saw that hole and put it through there. That's how good he is," Booth said. "I can't believe he put it through there."
Giving up a late lead was nothing new for the Panthers, who have allowed six tying or winning goals in the final minute this season.
Florida squandered two-goal, third-period goals in three consecutive games earlier this month.
"We've just got to be better and win some games," Jokinen said. "This is not fun."
The Panthers took a 3-2 lead at 11:45 of the third when Olesz scored five seconds into a power play.
Jay Bouwmeester's wrist shot from the point was blocked in front, and Olesz then beat Toskala with a backhand.
Toronto trailed 2-0 in the second period before Williams, recalled on Tuesday after the Leafs traded three players for draft picks, scored his third goal in three NHL games.
Williams took a pass from Sundin to the side of the net and beat Vokoun.
"He made a great goal," Sundin said. "He would have 100 goals if he played 100 games, it seems like. He's really smart finding the spot where the goalie has the holes."
Sundin tied it with a power-play goal at 2:49 of the third period. He took the puck along the boards and outmuscled defenseman Steve Montador to the front of the net before flipping the puck over Vokoun's right shoulder.
Cullimore opened the scoring at 9:27 of the first period when his wrist shot deflected off Williams. McLean made it 2-0 at 17:13 when he skated through three Toronto players and put the puck past a sprawling Toskala.
"We lost some momentum," McLean said. "Their top players really stepped up and made some plays for them. You have to give them credit, they continued to battle."
- Florida's Wade Belak played against his former team after being acquired in a trade Tuesday.
- Florida D Bryan Allen missed the game because of a leg injury sustained in Sunday's loss to the Rangers.
- Toronto D Bryan McCabe played in his 900th NHL game.
- C Kris Newbury also was recalled by the Leafs.
- Toronto won the season series 3-1.