NEW YORK _ The third review was a charm for the Islanders.
Two potential goals by Tom Kuhnhackl, including one in overtime, did not pass video review.
But a quick look at a possible offside on Josh Bailey's overtime winner at 4:39 confirmed the Islanders as 4-3 winners in Game 1 of their first-round series with the Penguins before a crazed sell-out crowd of 13,917 at NYCB Live's Nassau Coliseum on Wednesday night.
Game 2 is Friday night at the Coliseum.
Defenseman Justin Schultz, with goalie Matt Murray (31 saves) off for the extra skater, tied it at 3 from the left at 18:31 of the third period. Bailey tipped Cal Clutterbuck's feed off the post as he cut to the crease with two seconds left in regulation.
Defenseman Nick Leddy's blue-line floater had found a way past Murray as the Islanders took a 3-2 lead at 12:35 of the third. That came after the Islanders killed off a boarding call on captain Anders Lee after his skates got tangled with Erik Gudbranson's and the defenseman went hard into the end boards in the Penguins' zone before being helped to the dressing room.
Robin Lehner, in his third career playoff game and first since 2013, stopped 41 shots for the Islanders.
The Penguins have the playoff pedigree, having won back-to-back Stanley Cups in 2016 and 2017 and with Sidney Crosby and Evgeni Malkin also being part of the 2009 Cup champions as well as the 2008 team that lost to the Red Wings in the Cup Final.
But the Islanders, after allowing an NHL-low 196 goals, seemed to have been built for playing playoff hockey with their defensive mentality.
"We'll have to see," said Islanders coach Barry Trotz, who led the Capitals to the Cup last season. "I just know the way we had to approach this year was getting certain things fixed so that's the way we play. For us to change during the playoffs wouldn't make any sense."
Yet the game opened at a breakneck pace with space available for both teams to skate in what had been anticipated as a tight-checking series, particularly for the Islanders, who rely upon their defensive structure and don't have the offensive talent the Penguins possess.
But with the crowd still sustaining their pre-game cheering and "Let's Go Islanders" chants, Kuhnhackl, the ex-Penguin, hopped off the bench, picked up a loose puck in the neutral zone, skated into the offensive zone and beat Murray with a wrist shot 33 seconds into the first period.
It was deafening inside the Coliseum but only momentarily as the Penguins challenged the goal and it was overturned as it was ruled Kuhnhackl played the puck in the zone before Matt Martin cleared it.
Kuhnhackl also had a waved-off goal confirmed by review at 1:12 of overtime as he bowled into Murray with the net coming off its mooring.
The Islanders took a 1-0 lead for real at 1:40 as Jordan Eberle, open at the right post, knocked in the rebound of defenseman Adam Pelech's point shot. Phil Kessel tied the score at 1 at 5:42 as he beat Lehner from the slot after Casey Cizikas had fallen in the neutral zone.
But Brock Nelson's power-play goal at the crease off Eberle's feed at 15:46 gave the Islanders, who entered the playoffs 3-for-50 (6.0 percent) on the man advantage over their last 22 regular-season games, a 2-1 lead.
A second Islanders' power play at 5:43 of the second period produced four shots and also looked crisp until Mathew Barzal's turnover led to Kessel being sprung out of the penalty box, forcing Lehner to make a blocker save.
Leo Komarov's needless offensive-zone holding penalty led to Evgeni Malkin's power-play goal to make it 2-2 at 13:41 of the second period as his shot from the right circle went over Lehner's far shoulder after deflecting off defenseman Adam Pelech.
Lehner finished the second period strong, stretching to stop Nick Bjugstad at the crease at 15:47 and doing the same to Malkin at 18:38. Kessel did miss an open look at the crease seconds after Lehner's save on Bjugstad as his shot from the right hit the near post.
The Islanders' Matt Martin started the third period with a shot off the crossbar.