Anaheim tied it 2-2 with 35 seconds left in the first period. Beckett Sennecke swept a pass back to Pavel Mintyukov at the left point, and the defenseman brought the puck to the top of the left circle before making a cross-ice feed to Gauthier, who scored with a one-timer from the right circle.
Helleson put the Ducks in front 3-2 at 9:48 of the second period with a slap shot from the right point.
The Penguins responded to tie it 3-3 at 17:01 of the second. Crosby came off the bench and immediately got the puck on a short 2-on-1. He then passed over to Mantha, whose shot broke the stick of Anaheim defenseman Jacob Trouba before fluttering into the net.
The Ducks challenged the play for offside, but the call was confirmed after a video review.
"We had a good start and then it ends up being 2-2," Crosby said. "Special teams are going to be big and they were the difference tonight."
NOTES: Crosby has 1,065 career assists, passing Steve Yzerman (1,063) for ninth in NHL history. Crosby also passed Yzerman for the third-most assists with one franchise, trailing only Ray Bourque (1,111 with the Boston Bruins) and Wayne Gretzky (1,086 with the Edmonton Oilers). ... The Ducks have won 10 straight home openers, which is tied for the second-longest streak in League history. ... The announced crowd of 17,622 was the largest for a game at Honda Center in Ducks history. ... Penguins defenseman Kris Letang played 21:11 after being a game-time decision because of a lower-body injury. ... Penguins defenseman Connor Clifton had eight hits and four blocks in 18:21 of ice time in his team debut. ... Sennecke, who was the No. 3 pick in the 2024 NHL Draft, has two goals and two assists in his first three NHL games. ... Mantha's goal was his first since Nov. 3, 2024, when he played for the Calgary Flames. He tore his ACL in a game two days later that required season-ending surgery.