Michael Bunting extended the lead to 6-1 at 3:59 of the third period when his shot hit the post and was accidentally kicked in by Kings center Phillip Danault.
Durzi scored on the power play with a wrist shot from the high slot at 16:07 for the 6-2 final.
Durzi was drafted by the Maple Leafs in the second round (No. 52) of the 2018 NHL Draft and traded to the Kings for defenseman Jake Muzzin on Jan. 28, 2019. He was minus-2 in 15:52 of ice time.
"It was nice," Durzi said. "Obviously garbage time in the hockey game, but I thought to get it out of the way was good. There's a lot to clean up, but it was really good."
Alex Kerfoot scored off the rush on a backhand from the slot to give Toronto a 1-0 lead at 4:30 of the first period.
Viktor Arvidsson tied it 1-1 at 1:21 of the second period on the power play when Durzi's shot from the blue line struck his stick and skate before going in. It was Arvidsson's first point in four games after missing seven games in NHL COVID-19 protocol.
NOTES: Maple Leafs forward David Kampf did not return after being elbowed in the head by Kings forward Rasmus Kupari in the first period. Keefe said Kampf was taken out of the game as a precaution because of the nature of the hit. Kupari was penalized for tripping on the play. … Kings forward Andreas Athanasiou did not play after being placed in NHL COVID-19 protocol Wednesday. … Arvidsson was hit by pucks in the groin and collarbone. McLellan said Arvidsson was OK but bruised. … Durzi is the third defenseman in Kings history to score in his NHL debut (John English, one goal, two assists, March 30, 1988; Jean Potvin, one goal, two assists, Dec. 26, 1970). … Simmons and TJ Brodie each had two assists. … The Kings were 2-for-3 on the power play; the Maple Leafs were 1-for-3. … It was the first game Muzzin and Campbell played in Los Angeles since being traded to Toronto. Campbell, who was traded Feb. 6, 2020, backed up Frederik Andersen in a 1-0 shootout loss to the Kings on March 5, 2020. Muzzin did not play in that game because of a fractured hand.