Johnson, making only his third start since Dec. 22, was 16.5 seconds away from a shutout, but after a scrum in the Isles' zone, he skated down the ice to at the behest of New York goaltender Rick DiPietro -- and dropped him with one punch.
"The guys didn't know I had that little mean streak in me," said Johnson, who has 14 career shutouts, but had never fought in the NHL. "It was something I've kind of wanted to do for a while. Maybe it's just a little bit of frustration about some things.
"That was my first time in the NHL," Johnson said. "I had a couple fights in the minors and a lot in juniors."
"Johnny was sick," Fleury said of his backup's fistic skills. "He's a righty, first of all, and he goes in as a lefty. That was awesome. He was so calm, so relaxed. It was just boom! His expression never changed. It was just boom, and that was it."
DiPietro's face was visibly swollen with a welt after the game.
"It's a fight. Things happen," DiPietro said. "He's got long arms."
Pittsburgh has 11 consecutive home victories against the Islanders, who were angry long before the Johnson-DiPietro fight after being outplayed and outhit by the more-physical Penguins throughout the game. Blake Comeau laid on the ice for a few minutes after Talbot delivered a blind shoulder-to-shoulder hit in the first period.
"Looking at it, it was a dangerous hit," New York forward Zenon Konopka said. "We're not happy, and we're not happy with the outcome of the game. We have to remember this."
The teams meet again next Friday on Long Island.
Tyler Kennedy, Chris Kunitz and Talbot scored for Pittsburgh, which has won four consecutive and seven of eight -- all without captain Sidney Crosby (concussion). The Penguins have also been without All-Star center Evgeni Malkin (sinus infection) for five games. Malkin is expected back soon, but there is no timetable for Crosby's return. Pittsburgh is 7-3-1 without him.
Kennedy opened the scoring with his ninth goal and first since Jan. 12 at 8:08 of the opening period when the rebound of Paul Martin's power-play shot from the left point squirted to him in the lower right circle. Kennedy's shot from a bad angle near the boards near the bottom of the circle beat DiPietro.
The Islanders have allowed the first goal in 13 of 14 games and are 5-25-4 in games in which they trailed 1-0.
Kunitz made it 2-0 at 13:10 with his fifth goal in eight games. He drove down the right wing and took a backhander from the right circle that DiPietro misplayed. Kunitz has 10 goals since Dec. 23 and 18 on the season, the most he has scored since the 2007-08. He is seven shy of his career high.
Talbot added an empty-net goal in the final minute for his 100th career NHL point.
One of Johnson's best saves came midway through the third when he gloved a slap shot from the left point off the stick of Travis Hamonic. He also stopped Jack Hillen from in close in the final period.
Still, it was the goalie fight that drew most of the conversation after the game.
"I guess you don't see it that much in today's NHL, but obviously back when assistant coaches and I played you saw it all the time," Islanders interim coach Jack Capuano said. "It was one of those things. There was some scuffling going on toward the end of the game in the corner and I guess (Johnson) thought he had to come down."
Material from wire services and team media was used in this report.
1 - 0 PIT
2 - 0 PIT
3 - 0 PIT