Bo Horvat had a goal and two assists for the Islanders (14-7-8), who had a four-game winning streak end but extended their point streak to eight (6-0-2). Sorokin made 30 saves.
“That’s a good hockey game from us, for sure,” Islanders captain Anders Lee said. “Just doesn't go our way in the shootout. So regroup and be proud of what we did.”
Mason Lohrei scored at 16:51 of the third to tie the game for the Bruins at 4-4, banking the puck off Sorokin’s back and in from below the goal line to force overtime with his second NHL goal.
“Honestly, I didn't see it go in,” Lohrei said. “I just saw [Brad] Marchand in front start celebrating. I just jumped in on the rush. The puck got to the net. There was a bunch of chaos, and then went into the corner, and I just got in there. I knew Pastrnak was out front, so I thought just throw it to the net, and hopefully we get a whack, but I guess it just went in.”
Lohrei’s goal capped a wild third period in which the Islanders took the lead twice only to see the Bruins tie it each time.
Horvat beat Ullmark blocker side from the slot on the power play 5:06 into the third to give the Islanders a 3-2 lead. After a behind-the-back point feed from Mike Reilly to Brock Nelson inside the right face-off dot, Nelson found Horvat in the bumper position.
Van Riemsdyk tied the game at 3-3 at 10:48 on the power play following his redirection off a Kevin Shattenkirk point shot.
Nelson gave the Islanders a 4-3 lead on the power play when he put in a missed Horvat shot from the low slot at 12:01.
The Islanders took a 1-0 lead at 1:42 of the second period when Alexander Romanov scored on a wrist shot glove side from the top of the left circle after he received a drop pass from Mathew Barzal.
Simon Holmstrom gave the Islanders a 2-0 lead at 13:26 when he finished off an odd-man rush with Jean-Gabriel Pageau. In all alone, Holmstrom deked backhand to forehand before scoring blocker side.
After Ullmark robbed Holmstrom on a short-handed chance, Geekie scored on the power play to cut the Islanders' lead to 2-1 at 14:45. He finished off a Van Riemsdyk pass from the slot.
“We get a power play goal, and now we're back in it,” Montgomery said. “We needed the power play to get going offensively because we weren't doing anything outside the first five minutes. And then we started to feel a little bit of a rhythm, and then we started to support the puck hang on a little bit.”