DENVER -- The Colorado Avalanche fell apart in the third period of their season opener but wrote a different ending against the Dallas Stars on Saturday night.

Gabriel Landeskog had two goals and two assists, center John Mitchell scored a tiebreaking goal in the third period and the Avalanche rallied with five straight goals to beat the Stars 6-3.

Center Nathan MacKinnon had a goal and two assists and right winger Jarome Iginla and defenseman Erik Johnson also scored for the Avalanche. Goaltender Semyon Varlamov stopped 30 shots for Colorado.

It was a reversal of how the Avalanche played against Minnesota on Thursday. They led 4-1 after two periods, but the Wild scored four times in a span of 5:07 to stun Colorado.

After a slow start, the Avalanche erased that loss with their first win of the season.

"We showed a lot of character. That was important to me," Colorado coach Patrick Roy said. "It was a big night for our guys. You look at what happened in the third period against Minnesota, any team would be affected at the start of the game. But at the end, you get to see if you have character."

Center Cody Eakin scored his first two goals of the season and center Mattias Janmark also scored for Dallas.

"We just kind of let it go," Eakin said. "We started playing east-west a little bit. We kind of got a little complacent in our own end."

The score was tied at 3 after two periods before the Avalanche broke on top. Mitchell, who hit a post earlier in the third period, beat goalie Antii Niemi with a shot from the left circle at 8:11 to give Colorado a 4-3 lead.

"I wanted to make sure I was kind of staying in that low slot area, close to the net but not too close," Mitchell said. "They found a way to get the puck out to me and I just had to shoot as quick as I could. There were a lot of guys around me and not much time."

Landeskog gave the Avalanche a two-goal cushion with his second goal of the season at 8:58. The right winger got his second goal of the night and third of the season at 17:34.

"We lost too many battles. Our battles were just crap," Dallas coach Lindy Ruff said. "It's really disappointing. It's embarrassing. Worse than disappointing. Our best players have to be our best players."

The Stars, coming off a 3-0 victory over Pittsburgh on Thursday, took a 1-0 lead when Janmark struck early for the second straight game. He came down the slot, took a pass from defenseman Jason Demers and beat Varlamov with a backhander 20 seconds into the game. It was the rookie's second goal of the season.

The Avalanche tied it when MacKinnon got behind the defense, got a pass from right winger Alex Tanguay and scored on Niemi at 9:06 of the first period.

Eakin gave the Stars a 2-1 lead 1:15 later when he scored from close in, and his power-play goal at 8:50 of the second period gave Dallas a two-goal advantage.

"It's frustrating. We have a 3-1 lead and we were pretty much in control up to that point," Stars center Jason Spezza said.

The Avalanche quickly tied it with two power-play goals. Johnson cut Colorado's deficit to one with a slap shot from the point at 14:53 of the second period. Later in the period, Dallas was given a bench minor for too many men on the ice and Iginla cashed in with his second goal of the season at 17:51.

"We knew we definitely have enough skill and grit in this room to turn around a two-goal deficit," Landeskog said. "We were up three goals last game with about 10 minutes to go, and we were down two (tonight) with about half the game left, so there was a lot of hockey to be played. Our power play did a good job swinging the momentum our way and we just fed off it."

NOTES: Avalanche D Brad Stuart and Brandon Gormley were healthy scratches for the second straight game. C Mikhail Grigorenko also was scratched. ... C Mattias Janmark's goal 1:39 into Thursday's win was the second fastest goal by Stars rookie in franchise history. Bob Barlow scored his first goal 1:08 into his NHL debut on Oct. 11, 1969, vs. Philadelphia. ... Colorado RW Jarome Iginla tied Chicago great Stan Mikita for 36th in games played with 1,394. ... Dallas D Patrik Nemeth, D Jamie Oleksiak and C Colton Sceviour were scratches. ... Avalanche C Jesse Winchester remains sidelined because of concussion symptoms. He missed last season because of the condition.