Nelson had two goals and an assist, Nick Leddy had three assists, Anthony Beauvillier had a goal and an assist, and Semyon Varlamov made 27 saves for the Islanders (15-3-1), who are 14-0-1 since losing 5-2 to the Carolina Hurricanes on Oct. 11. New York has had a 15-game point streak three previous times with the most recent coming Jan. 21-Feb. 20, 1982 (15-0-0).
"Honestly, and this is with all true honesty, we wouldn't even know," Islanders coach Barry Trotz said. "Our team would have no clue if we won 10 in a row or five in a row. We would just know we haven't lost in a while. That's really been our mentality. But everyone in the media seems to keep bringing that up, so we're understanding the numbers now."
WATCH: [All Islanders vs. Penguins highlights]
Matt Murray made 37 saves for Pittsburgh (11-7-3), which is 3-1-2 in its past six games. Brandon Tanev had two goals, Jake Guentzel had a goal and an assist, and Evgeni Malkin had two assists.
"I didn't think we were very good at all [in overtime]," Penguins coach Mike Sullivan said. "I just thought our details were brutal. So we have to be better."