McGinn scored on the Penguins' first shot of the game, giving them a 1-0 lead at 5:12 of the first period. After entering the zone, Zach Aston-Reese sent a backhand pass to the left face-off circle to set up McGinn for a one-timer glove side.
"I think I just want to come out and play my game," McGinn said. "I always believed in my offense, but in Pittsburgh, I feel like I have a lot more confidence in my game and a lot more confidence with the puck."
Pittsburgh didn't have another shot until a slap shot from Crosby on a power play at 11:24 of the first. It was held to six shots on goal in the period.
Troy Terry had a chance to tie it after he stickhandled around Penguins defenseman Kris Letang at 7:33 of the second period. He went from his backhand to his forehand with DeSmith unable to get back to the post, but couldn't get off a shot into an open net.
"There's games like that," said Terry, who leads the Ducks with 15 goals. "For me, personally, there were some games this year where maybe I had one scoring chance and I scored on it. It's just how it goes.
"It's hard not to get frustrated. But after the game, I had a second to think. I keep [generating scoring chances], myself personally, I'm going to score goals. Our line's going to score goals. We had lots of chances."
The Penguins have allowed two goals or fewer in nine of their past 11 games.
"I think the players have just done a terrific job," Pittsburgh coach Mike Sullivan said. "These guys are committed. They want to win. They understand that if we're going to win games consistently, we can't just rely on scoring goals."
NOTES: Penguins forward Danton Heinen had two shots on goal in 14:28 of ice time in his first game against his former team since signing a one-year contract with Pittsburgh on July 29. He had 18 points (10 goals, eight assists) in 52 games with the Ducks the previous two seasons. … Ducks forward Isac Lundestrom played his 100th NHL game. He has 30 points (13 goals, 17 assists) in the NHL. … After killing each of Anaheim's two power plays, Pittsburgh has not allowed a power-play goal in a franchise-record 13 straight games. The Penguins' NHL-best penalty kill (92.4 percent) has killed 30 straight power plays.