In his first game back from a lower-body injury that kept him out for 15 games, Vatanen assisted on Corey Perry's goal 1:25 into overtime to give Anaheim a 3-2 win against the Colorado Avalanche at Honda Center.
Perry beat Colorado goalie Semyon Varlamov to the glove side with a wrist shot on a breakaway for his 29th goal after Vatanen poked the puck free from Colorado defenseman Brad Stuart at the Anaheim blue line.
"Sami made a great play at the blue line, got his stick on the puck and poked it ahead," Perry said. "I was fortunate to have that breakaway. I had an idea of what I wanted to do and found a way [to score]. He probably scouted what I do on breakaways too.
"I have a couple of shots I like to do and I picked one."
Vatanen cost the Ducks in the third period when the puck hopped over his stick and resulted in a shorthanded goal by Colorado's Ryan O'Reilly. But Perry erased it with sixth career overtime goal, which tied him with Teemu Selanne and Ryan Getzlaf for the franchise lead.
"I think I've been lifting too much bench press at the gym, so my hands were a little bit frozen there and it bounced over my stick," joked Vatanen, who played a team-high 22:21. "Sometimes that happens and you've got to just re-focus and do your thing again. It was my bad, but we got the 'W.'"
The line of Jiri Sekac, Rickard Rakell and Tomas Fleischmann combined for two goals and an assist for the Ducks (46-20-7), who are the first team in the NHL to reach 99 points. Anaheim leaves Saturday for a five-game, nine-day trip.
"It's going to be a happy plane ride," Perry said.
It was the third straight game in which Anaheim erased a third-period deficit to win. The Ducks are 29-1-7 in one-goal games this season.
"I don't know if we expect to win, but we dig down and work harder," Anaheim coach Bruce Boudreau said. "But I think the belief that it's possible is the thing that always gives you a chance. If you never thought it was possible, then it doesn't happen."
Varlamov made 37 saves for the Avalanche (33-26-12), who got one point and are six points back of the Winnipeg Jets for the second wild card into the Stanley Cup Playoffs from the Western Conference.
"We're playing hard and we're playing well," forward Matt Duchene said. "It's too bad we couldn't have got that one, but three out of four on the road in a back-to-back situation, you know it's not bad.
"I think we're happy, but we're not over the moon about it. We put ourselves in a situation to win that game. It's too bad we couldn't have."
Varlamov started on consecutive nights and for the 26th time in 27 games, having missed March 10 with injury. Colorado coach Patrick Roy said he's been invaluable with 399 man-games lost, the second-most in the NHL.
"It just tells you how important the goaltender becomes, and it is important for us to count on [Varlamov] every night, and he's been doing just that," Roy said.
Rakell tied it 2-2 when he beat Varlamov with a wrist shot from the left circle at 9:04 of the third period. Rakell poked the puck free and pivoted into position for his seventh goal this season.
Colorado erased a 1-0 deficit with two goals in 1:51 of the third period by Jarome Iginla and O'Reilly. Iginla one-timed Duchene's saucer pass from the slot past Ducks goalie Frederik Andersen for his team-leading 24th goal at 5:28 after Duchene grabbed the puck at the half-wall off a dump-in.
O'Reilly scored his fourth career shorthanded goal at 7:19 when he took a loose puck that hopped over Vatanen's stick at the blue line, raced past him and used a backhand-forehand move to beat Andersen.
"It was a nice little bounce," O'Reilly said. "They just mishandled the puck. I just tried to get speed when I saw a clear-cut breakaway, so just trying to get going with speed. He's a good goalie. I had to do a quick move. I just thought backhand to forehand, get it over and luckily it went in."
Sekac scored his first goal as a Duck 3:37 into the game with a turnaround shot that banked off Varlamov. Sekac, acquired from the Montreal Canadiens on Feb. 24, has been scratched the previous game.
"We just tried to play with a lot of speed, and puck control," Rakell said of his line. "We knew that if we get the puck down low and start twisting and turning down there, we're going to get a lot of chances, and that's what happened."