OTTAWA — The Ottawa Senators were able to pull off the unexpected Friday night.

The Senators mounted an unlikely comeback, scoring four unanswered goals to beat the San Jose Sharks 6-5 in overtime.

Matt Duchene scored his second of the game seven seconds into the extra period to give Ottawa a much-needed victory.

"I think we finally got rewarded for the things we've been doing," said Duchene. "We've had some tough stretches defensively and offensively, but we've been doing a lot of good things for a while and it hasn't been going in. It's nice to see that happen. We had a lot of guys step up for us.

"Once we made it 5-4 I think we felt like we were going to win the game."

Down 5-2 to start the third period, the Senators (13-17-9) got goals from Derick Brassard, Duchene and Mike Hoffman to tie the game. Ryan Dzingel and Mark Stone also scored for Ottawa and Craig Anderson made 30 saves.

Tomas Hertl led the Sharks (21-13-5) with two goals. Melker Karlsson, Chris Tierney and Brett Burns also scored. Aaron Dell stopped 37 shots.

Brassard made it 5-3 in the opening minute of the third, beating Dell from a sharp angle. Duchene cut the lead to one, scoring off his backhand and Hoffman tied the game with his first goal in 15 games, midway through the period to send the 16,061 at Canadian Tire Centre into a frenzy. The Senators fired 17 shots in the third period alone.

"We felt like we were still in the game and playing well," said Stone. "Obviously that third goal helps, you get a lucky bounce and I think it energized the bench a bit. Then we score one before the ten-minute mark and ultimately start putting the pressure on them."

The Sharks were coming off a 3-2 shootout loss to the Leafs, but weren't using that as an excuse for a third-period letdown of this magnitude.

"It doesn't matter how tired we are," said Joe Pavelski. "A three-goal lead like that we expect to win that game and we didn't. We're not going to hang our head or anything like that. It's about us. We definitely had enough energy to play better than we did in the third period."

The Sharks took a 4-1 lead early in the second, scoring back-to-back power-play goals.

Anderson gave up a big rebound and Tierney was there to pick it up, beating the goalie glove side. Less than two minutes later, Burns took a great pass from Logan Couture and beat Anderson with a one-timer for his seventh of the season.

The Senators got one back on the power play as Dzingel found Stone, who beat Dell far side.

San Jose regained its three-goal lead on Hertl's second of the night as Anderson struggled to handle a bouncing puck on a wraparound and watched it bounce in through his legs.

San Jose scored the game's first goal while shorthanded. Hertl, on a breakaway, scored his first of the game at the six-minute mark.

The Senators tied the game on a nice goal by Dzingel but the Sharks regained the lead just over two minutes later when Karlsson tipped in Joakim Ryan's point shot.

Ottawa's Nate Thompson left the game early in the first with a lower-body injury and did not return. He is not expected to play Saturday.

The Senators have little time to enjoy the victory as they host the league-leading Tampa Bay Lightning Saturday night.

Last Friday the Senators posted a 5-4 victory over Columbus, but followed it up the next night with a 5-0 loss to Boston. Ottawa has a 3-3-2 record in the second half of back-to-back games.

"I think we've got to use the energy from tonight and the things that we did right," Duchene said. "Tonight was a fun game. That third period was probably the most exciting third period I've been a part of and if we can't draw any energy from that then something's wrong."

Notes: Ottawa C Zack Smith returned to the Senators lineup after missing the last five games with a shoulder injury. D Fredrik Claesson was a healthy scratch. Sharks RW Joel Ward was a healthy scratch to give the veteran the night off.