DeMar DeRozan had 13 points and 11 rebounds to help the Raptors win their fourth straight game.
Lowry made two free throws to put Toronto up 105-100 with 43 seconds left in overtime, but Oladipo answered with a 3-pointer. After Lowry missed a shot, he stole the ball from Oladipo and was fouled by Tobias Harris. Lowry made one of two, making it a three-point game.
Vucevic had 17 points and 11 rebounds for the Magic, and Harris had 16 points and 11 rebounds.
Down 88-77 with 7:34 left, the Magic tied it at 96 on Oladipo's jumper with 32.9 seconds left.
After a miss by Lowry, Oladipo had a chance to win it, but missed a 21-foot jumper with less than a second to go. A replay review gave possession to Orlando, but Jason Smith bounced a shot off the rim as the buzzer sounded, sending it to overtime.
Orlando's Elfrid Payton came off the bench, returning after sitting out the past four games with a bruised left ankle. Forward Aaron Gordon played despite rolling his right ankle during practice Wednesday.
Before the game, and after the playing of "O Canada," "The Star-Spangled Banner," and "God Save the Queen," Lowry and Vucevic stood at center court and briefly spoke to the crowd, thanking the fans for their support.
Raptors: The last time the Raptors visited London, back in March 2011, they lost in triple overtime to the Nets, a game where DeRozan and former Raptors center Andrea Bargnani both missed last-second shots.
Magic: Orlando came in 8-0 against Atlantic Division opponents. ... G Shabazz Napier (illness) was not available.
Raptors: Host Brooklyn on Monday night.
Magic: Visit Atlanta on Monday.