Adam Pelech, Anders Lee and Jordan Eberle also scored for the Islanders, who snapped a three-game losing streak and won for just the third time in their past 14 games (3-7-4). The Islanders moved out of sole possession of last place in the Metropolitan Division and into a tie for seventh with the New York Rangers.
Goalie Christopher Gibson earned his third career win by recording 36 saves.
Conor Sheary scored for the Penguins, who are tied with the Columbus Blue Jackets for second place in the Metropolitan Division. Goalie Matt Murray, who missed the previous nine games with a concussion, made 36 saves.
Barzal belatedly received credit for the Islanders' first goal, which was originally awarded to Johnny Boychuk 5:10 into the opening period. However, replays showed Boychuk's shot ticked off the stick of Barzal as Barzal cut toward Murray in front of the net.
There was no doubt about the Islanders' second goal at 10:33 of the first, when Pelech took a no-look pass from Tanner Fritz and fired a sizzling slap shot over Murray's glove.
The Penguins cut the gap in half with their own resounding goal late in the second period. Phil Kessel's pass across the crease went past Islanders defenseman Nick Leddy and to Sheary, who went to one leg in the middle of the left faceoff circle and, with Leddy still facing the net, uncorked a shot that sailed over Gibson's glove with 2:46 left.
Lee extended the lead back to two with a power-play goal 5:41 into the third. Barzal passed to Lee, who was stationed to the right of Murray and backhanded a shot under the goalie's stick.
Eberle sealed the game for the Islanders by scoring an empty-netter with 2:29 left.
--Field Level Media
Pittsburgh | NY Islanders | |
Conor Sheary 1 | Points | Mathew Barzal 2 |
Conor Sheary 1 | Goals | Mathew Barzal 1 |
Derick Brassard 1 | Assists | John Tavares 2 |
N/A | Power Play Goals | Anders Lee 1 |
N/A | Short Handed Goals | N/A |
Matt Murray .923 | Save Percentage | Christopher Gibson .973 |
Matt Murray 36 | Saves | Christopher Gibson 36 |
Team | Shots | Goals | Power Play | Penalty Kill | Penalty Mins | Face Offs Won |
Pittsburgh | 37 | 1 | 0-1 | 4-5 | 12 | 33 |
NY Islanders | 40 | 4 | 1-5 | 1-1 | 4 | 30 |