Watch Now:

BOSTON -- Thanks largely to the unexpected heroics of rookie Sean Kuraly, the Bruins have life and their first-round playoff series with the Ottawa Senators returns to Boston for Sunday's Game 6.

But despite Boston's double-overtime win Friday night, Ottawa still leads the series 3-2.

"We just stay the course. It's exactly what we expected -- tough, hard series," Ottawa coach Guy Boucher said before his team left for a return trip to Boston the Senators had hoped to avoid.

" ... We rebounded all year. There's no reason why we can't rebound again."

The Senators, who finished second in the Atlantic Division ahead of the third-place Bruins, have won five straight games at TD Garden. They are 7-2 overall against Boston this season.

The Senators took Game 3 in overtime and won 1-0 in Game 4, with Bobby Ryan scoring the winner in both games.

"It's a great stat, but I don't think we think about it much to be honest," Ottawa's Marc Methot said of his team's success at TD Garden. "During the regular season, that's one thing, but it's a different ballgame now."

And the Bruins, who have never come back from a 3-1 deficit to win a playoff series -- losing all 22 previous times they faced that climb -- have life.

And they have it at least partially because interim coach Bruce Cassidy played a hunch and inserted Kuraly, whose rights were acquired in a 2015 deal that sent goaltender Martin Jones to San Jose, into the lineup after he sat out the two games in Boston.

Playing in only his 11th NHL game, Kuraly scored the tying goal from behind the net as the Bruins completed a comeback from two goals down, and then had the winner on a rebound past Craig Anderson.

Kuraly then started jumping up and down as his teammates came off the bench in celebration.

"It was really cool to see," teammate Kevan Miller said. "He looked a little bit like 1980 Miracle, running around the ice."

"I'd say it's a huge momentum lift for tomorrow," said defenseman Joe Morrow, who like Kuraly is playing because of injuries to others. "Playing at 3 (p.m.) you're right back at it, take care of your bumps and bruises today.

"You wake up tomorrow ready to play another game and you're still kind of coming off the high of winning that game in overtime and seeing some guys make some huge plays and be super excited about that. That's what we're going to carry into tomorrow."

Both teams have manpower situations heading into Game 6. The Bruins, already missing three of their top four defensemen, also lost David Krejci again in Game 5 -- this time on a knee-on-knee hit by Chris Wideman.

As Krejci left the ice, Bruins players detected Wideman mocking Krejci, who also missed the first two games of the series.

None of the three defensemen will return for Game 6, although Torey Krug is skating and could be possible for a Game 7. Krejci was getting treatment Saturday and is officially day to day.

Ottawa's Victor Stalberg went down with an injury Friday, joining Tom Pyatt and Mark Borowiecki on the Senators' injury list. Borowiecki was injured in Game 2, Pyatt in Game 4.

"I just need to know who's available," Boucher said.

Of the nine games the teams have played this season, only seven have been decided by one goal, one of the two two-goal decisions included an empty-netter, and four have required extra time.

Speaking Friday night about Kuraly, Cassidy said, "I liked his game early in the series, but we had guys that had been here. You know Krech came back in the lineup, he's obviously going to play. So we liked him, we just kind of put guys ahead of him that have been here all year.

"One door closes, another one opens, and he took advantage of his opportunities starting at the bottom of the lineup. Tonight, we just needed him more."

Copyright 2017 by Associated Press. Any commercial use or distribution without the express written consent of Associated Press is strictly prohibited.