Mathew Barzal and Brock Nelson each had a goal and an assist, and Ilya Sorokin made 37 saves for the Islanders (23-18-14), who had lost three in a row (0-1-2).
Erik Karlsson had an assist to reach 800 NHL points, and Valtteri Puustinen and Drew O'Connor scored 56 seconds apart to tie it late in the third for the Penguins (24-21-8), who have lost five of six. Alex Nedeljkovic made 28 saves.
“It's a tough one,” Pittsburgh coach Mike Sullivan said. “It's disappointing because I think our team competed really hard. ... There was a lot to like about our team game tonight. I thought it was an inspired effort."
After Mike Reilly scored on a wrist shot, extending New York’s lead to 4-2 at 10:42 of the third, Puustinen stuffed in a rebound from the crease to cut it to 4-3 at 12:06.
O’Connor tied it 4-4 at 13:02 with a cross-ice pass that went in off the skate of Islanders forward Anders Lee in front.
"It was a good pushback,” Penguins captain Sidney Crosby said. “Not the ideal situation to be in, but we battled hard and got it even. ... Take the point and move on. We need points, so we got one. We've got to continue to grab them."
Marcus Pettersson put Pittsburgh ahead 1-0 at 12:48 of the first period on a one-timer from the right face-off circle.
Karlsson had the secondary assist for his 800th point in 973 games (185 goals, 615 assists).
Nelson tied it 1-1 at 3:40 of the second period, skating past Karlsson and Pettersson to the slot and shooting a backhand.
Barzal gave the Islanders a 2-1 lead at 6:37 with a wrist shot on a breakaway after exiting the penalty box. He has 11 points (five goals, six assists) on an eight-game point streak.
“We really have to find a way, because we're in every single hockey game and we really do have the lead [a lot],” Barzal said. “Have to find a way to just get over the hump. It's nice to get the win tonight, but it shouldn't have gotten there (overtime). Have to find a way to get better."
Simon Holmstrom extended it to 3-1 at 13:15 with a wraparound after Karlsson turned the puck over behind the net.
Lars Eller cut it to 3-2 with a snap shot that deflected off Pelech at 16:35.
“There’s no quit. We don’t give up,” Eller said. “We’ve got to keep the faith and the belief. It’s tough right now when you only get one point. But we showed that we have no quit in us, regardless of how things went during the game. That’s going to be important going forward, the mentality of never stop fighting.”
NOTES: Karlsson is the 18th defenseman in NHL history, and ninth fastest, to get to 800 points. He is the second active defenseman to do so, joining Brent Burns of the Carolina Hurricanes (869 points; 254 goals, 615 assists). ... Islanders forward Casey Cizikas left the game after blocking a shot from Karlsson off his hand 15 seconds into the third. Roy did not provide an update. … Barzal got his 19th overtime point, second to John Tavares (23) in New York history.
