The Sabres led 2-0 early after overcoming some very early pressure from Edmonton. At the 4:08 mark of the first period, Okposo deflected in a Marco Scandella slap shot, giving him goals in back-to-back games. Then with 9:17 left in the opening period, Larsson jumped on a rebound and scored his third of the year just after the Sabres were able to transition an Oilers opportunity back up the ice.
Edmonton matched Buffalo's two-goal first period with a pair of goals of their own in the second. Riley Sheahan scored to make it 2-1 at 8:25 of the second period when he collected a long stretch pass from the Edmonton blue line and score on a breakaway.
Then with 4:03 remaining in the second, Joakim Nygard set up one half of a double screen and redirected a shot from Darnell Nurse into the back of the net on the power play.
Oilers captain Connor McDavid started the third period off with two great chances against Ullmark, including one off the crossbar. And with 6:58 left, Leon Draisaitl hit post.
In the overtime period, Marcus Johansson was able to find Miller with a feed through the Edmonton goal crease. Along the left post, Miller was able to gather the puck and put it past Mike Smith to give Buffalo the extra point.