Nathan MacKinnon had a goal and two assists, and Philipp Grubauer stopped 30 shots for the Avalanche.
“He made some really big saves,” Rantanen said. “One breakaway save, I think that was the highlight. He kept it a 3-2 game. It was a really good game from him. He made some big saves in the OT, too.”
Sven Andrighetto and Gabriel Landeskog scored the other Colorado goals.
Brandon Montour, Ryan Getzlaf and Ondrej Kase scored for Anaheim. Backup goalie Ryan Miller made 38 saves.
Landeskog tied it 3-all at 11:20 of the third period, taking a nice feed from behind the net.
“We kind of felt like we had more to give going into the third period,” Bednar said. “We come up with a big power-play goal at the end of the second to get within striking distance, then came out and won the third.”
The injury-riddled Ducks played with four rookie defenders and had to use Miller when normal starter John Gibson came down with the flu. They called up three players from their development team in San Diego before the game.
“We have all the confidence in the world with guys coming up,” Montour said. “They’re getting their experience. It’s good for us.”
The Avalanche, meanwhile, have won three of four. Their first line of Rantanen, MacKinnon and Landeskog is the top-scoring line in the NHL and it began to dominate from the third period on.
Pontus Aberg was penalized for slashing MacKinnon with 15 seconds on the clock in overtime, and Rantanen wasted little time making the man-advantage count.
“You just kind of had the feeling with some of the chances that they started to create that they’d be difference-makers,” Bednar said. “And then they end up getting a couple goals for us, a couple big goals for us.”
The Ducks led 3-2 after a high-scoring second period.
Colorado tied it at 1 when Andrighetto got a pass from Patrick Nemeth and slipped the puck past Miller.
Anaheim regained the lead with a power-play goal a minute later as Getzlaf fired a slap shot from long range that beat Grubauer up high. The Ducks made it 3-1 when Montour came down the right side and sent a wrist shot that Kase deflected in for his first goal of the season.
Just 4:34 into the second, Montour had a career-high three points (one goal, two assists).
“I thought we executed with the puck early in the game,” Anaheim coach Randy Carlyle said. “We had some questionable plays later where we seemed to get a little soft with it. There were more pucks bouncing and rolling around.
“They came with more pressure. They got on us, and we didn’t execute quite to the same level in the last half of the game.”
The Avs pulled within one on a power-play goal of their own as MacKinnon put in a rebound for his 13th of the season.
The Ducks opened the scoring 4:45 into the first on Montour’s goal. Aberg fired a shot from 40 feet out and the rebound came to Montour. He took the puck in stride, skated behind the net and slipped in a wraparound past Grubauer.
NOTES: It was just the fourth time in their last 15 games that the Ducks scored first. Anaheim has scored more than three goals only once this season. … Ducks defenseman Hampus Lindholm was scratched with a lower-body injury. … Anaheim defenseman Cam Fowler had surgery Friday for fractures in his cheekbone, upper jaw and orbital bone. The team has not announced a timetable for his return.
Avalanche: At the Los Angeles Kings on Wednesday night.
Ducks: Host the Vancouver Canucks on Wednesday night.
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