OTTAWA - The Ottawa Senators didn't like the way they started things Thursday night, but they were more than happy with how they ended.

The Senators scored four unanswered goals to defeat the Colorado Avalanche 5-3 in Ottawa's home opener.

"We were frustrated after the first, there's no question," said Clarke MacArthur, who scored the winner. "We slowed things down a little bit in the second and started to make the easy plays and we got a little momentum that way and started getting pucks to the net so that was good."

Bobby Ryan, Zack Smith and David Legwand also scored for the Senators (3-1-0) as Craig Anderson faced 31 shots. Chris Neil added some insurance with an empty-net goal.

Alex Tanguay, John Mitchell and Gabriel Landeskog scored for the Avalanche (1-3-1). Calvin Pickard faced 28 shots in his NHL debut.

Pickard was called up earlier in the day from the American Hockey League's Lake Erie Monsters after the Avalanche placed Semyon Varlamov on injured reserve. Pickard wasn't expected to see any action, but Colorado lost backup Reto Berra before the game was three minutes old. Berra was knocked over by Ottawa's Kyle Turris, who was pushed by Mitchell.

"It was probably a good time for a debut because you didn't have to think about it, you got right into it," said Pickard. "It was a fun atmosphere, good Canadian building and it was a good experience, but I would have liked to get the win for sure."

Avalanche coach Patrick Roy couldn't fault Pickard's play, but he wasn't overly impressed with some of his players.

"We can't be happy about our game overall," said Roy. "With the lead we had 13 turnovers. If we do turnovers when we're up by one goal eventually the puck's going to end up in the net. We have to be better with the lead; we have to be a lot smarter than that.

"I didn't think we managed our game very well."

Overall, Pickard was solid for the Avalanche, but the Senators scored two quick goals in the third to take control of the game and bring the 19,913 on hand at the Canadian Tire Centre to their feet.

After being robbed by Pickard in the second, Ryan made the most of a second opportunity and beat the 22-year-old through the legs to tie the game. Just over three minutes later MacArthur scored to give the Senators a 4-3 lead, their first of the game.

"To be honest that's kind of what we expect them to do," said Senators coach Paul MacLean. "As the leadership group of the team and the skill level of the team, that when the game is on the line and they have it on their stick the expectation is that they're going to make plays to give us a chance to win the game and they certainly stepped up and did that."

Trailing 3-1, Ottawa made it a one-goal game early in the second as Legwand scored a power-play goal, his first as a Senator.

Anderson and Pickard were the difference for their respective teams the rest of the way in the second.

Anderson made four consecutive saves late in the period, while Pickard's best came at the 17-minute mark as he slid across and robbed Ryan.

Ottawa struggled in the first and the Avalanche took advantage to take a 3-1 lead.

"I don't know if we were nervous in the first or what we were doing, but we didn't play hard enough and we didn't win the one-on-one battles," said Senators captain Erik Karlsson. "We came in (after the first period) and no one was happy with how we played and we just kind of had it out and had some words and took a deep breath after and (MacLean) came in calm and gave us directions of what to do in the second and we just came out and executed."

Colorado jumped out to an early 1-0 lead as Tanguay grabbed a loose puck and beat Anderson high. Colorado made it 2-0 at the halfway mark as Mitchell scored shorthanded after beating Karlsson in a foot race.

Ottawa cut the lead in half as Smith tapped in Curtis Lazar's shot, but after going 0 for 13 on the power play this season the Avalanche finally managed to score with the man advantage as Landeskog scored from in close.

Lazar had been anxiously waiting for this night and he maintained his enthusiasm throughout the game.

"Curtis certainly had an impact on the game and showed great enthusiasm to be playing here in Ottawa in front of the fans," said MacLean. "He really was a force for our team and a big reason why we won was the play of his line with Zack Smith and Milan Michalek, which I thought was probably the most consistent line that we had from start to finish."

Colorado will look to end this four-game road trip on a high as they head to Montreal to take on the Canadiens Saturday night, while the Senators will host Columbus.

Notes: The Senators will be without D Marc Methot (back, indefinite). D Jared Cowen, LW Mike Hoffman and LW Colin Greening were a healthy scratch for Ottawa. The Avalanche placed G Semyon Varlamov on injured reserve prior to the start of the game. Colorado was also without LW Patrick Bordeleau (back). Golfers Brad Fritsch and Brooke and Brittany Henderson were on hand for the game.