Lupul's -- his second tally of the contest -- came with only 31 seconds left after Toronto had pulled its goaltender to add a sixth attacker.
Then in overtime, the Oilers turned the puck over in the neutral zone and the Leafs came in on a 3-on-1 break. Cody Franson's initial shot was turned aside by Devan Dubnyk, but Bolland put home the rebound for the game-winner.
Van Riemsdyk also scored twice, while Nazem Kadri added a goal and an assist for Toronto, which is off to a 5-1-0 start.
Jonathan Bernier stopped 26-of-31 shots for the Leafs.
Dubnyk finished with 20 saves.
Notable deaths of 2014 [PHOTOS]
Michael Sam cut from the Dallas Cowboys