Vincent Trocheck, Daniil But and MacKenzie Weegar each scored and Karel Vejmelka made 22 saves for the Mammoth (5-2-0), who are 3-1-0 in their past four games.
Auston Matthews and John Tavares each had a goal and an assist, Gavin McKenna scored and Anthony Stolarz made 23 saves for the Maple Leafs (3-3-1), who were 2-0-1 in their past three games.
Tavares cut it to 5-3 at 7:12 of the third period when he took a lead pass from Stolarz, skated into the Mammoth zone and shot over Vejmelka’s glove from the left dot for the power-play goal.
The Maple Leafs made it 5-4 at 11:01. On a delayed penalty with Stolarz pulled for a 6-on-5 advantage, McKenna extended his point streak to four games (two goals, three assists) when he took a pass from William Nylander and shot past a sprawling Vejmelka’s glove from below the left dot.
Utah killed off the final 1:46 with Guenther in the penalty box for tripping and Stolarz pulled for a 6-on-4 advantage.
The Mammoth went up 1-0 at 14:55 of the first period when But stepped around Toronto defenseman Morgan Rielly at the blue line and shot short side on Stolarz from below the right face-off dot.
Trocheck pushed it to 2-0 at 1:00 of the second period. He dropped a backhand no-look pass to Logan Cooley, who returned the pass to Trocheck past a sprawling Darren Raddysh for a tap in at the top of the goal crease.
Sergachev made it 3-0 at 4:01 when he scored short-handed, putting a loose puck past Stolarz at the side of the net after Barrett Hayton’s initial shot was blocked by Toronto defenseman Nick Blankenburg.
Matthews scored 1:15 later on the power play to cut it to 3-1. When all four Mammoth penalty killers got caught on the same side of the ice, Tavares slid a pass to Matthews, who was alone in front of the net, and he deked to the backhand to put it past Vejmelka.
The Mammoth made it 4-1 at 14:17 when Guenther snapped a shot past Stolarz’s blocker from the top of the right face-off circle.
Jack Roslovic pulled the Maple Leafs to within two goals at 16:29. Matthews centered a pass to Kirill Marchenko in the slot from behind the net. Marchenko then spun and put a no-look backhand pass across to Roslovic, whose shot went off the goal post and in to cut it to 4-2.
Weegar made it 5-2 at 19:20 when he took a drop pass from Clayton Keller and shot between Stolarz blocker and chest protector from the left face-off dot.
