OTTAWA -- Dion Phaneuf has played 936 NHL games but never has he experienced a moment similar to the one he lived Saturday afternoon at Canadian Tire Centre.

"That's the biggest (goal) I've scored," said Phaneuf, the Ottawa defenseman whose shot from the point at 1:59 of overtime gave Ottawa a series-evening 4-3 victory over the Boston Bruins. "It feels great to do it here, in front of our fans. Just incredible.

I've played a long time and it's my first overtime winner. It feels great."

The first-round best-of-seven now switches to Boston for Games 3 and 4 on Monday and Wednesday.

The Senators rallied from a 3-1 third-period deficit with goal 2:20 by Chris Wideman and Derick Brassard.

"They're at home, they're desperate, they're going to push hard and they did," Bruins coach Bruce Cassidy said. "We didn't attack enough, I thought, or when we had opportunities we were off net with our shots to extend the lead or create havoc in their end.

"We just didn't have urgency they had. That's what generally happens. We saw the same script on Wednesday. We did it to them."

Clarke MacArthur also scored for Ottawa. Drew Stafford, Tim Schaller and Patrice Bergeron replied for the Bruins.

Craig Anderson made 26 saves in the Senators net while Tuukka Rask stopped 25 shots for the Bruins.

The Senators lost Mark Borowiecki with a lower-body injury in the first period, leaving with only five defenseman. The banged up Bruins' blue line took another hit when Adam McQuaid also left the game in the first.

MacArthur's goal was his first since April 19, 2015. The veteran winger has missed all but eight games during the last two years while he has been battling to come back from concussion problems.

"You could feel it coming," he said. "I was getting opportunities the last few games. It's a great feeling. It was a lot of weight lifted off me, getting that. Those ones in two-on-two after practice don't feel as good as that.

"It's nice to know that I can still do it. Hopefully, there's more to come."

The Bruins built their lead in a four-goal second period that saw them score. Stafford scored just before MacArthur's goal and Schaller took the energy out of the building when he clicked on a short-handed effort less than two minutes after it.

"I just played the puck behind the net and it took a bad bounce off the backboards," Anderson said. "Their guys came hard.

"It's behind us. We battled back."

The Senators' rally started at 5:28 of the third period on Wideman's seeing-eye wrist shot from the point.

Brassard evened the score on a magnificent set up by Erik Karlsson. Taking the puck at the right point, Karlsson quickly skated along the blue line and then toward the net. With Bruins in pursuit, Karlsson made a pass back through the slot to Brassard, who one-timed a shot in the open side.

"I think Erik displayed the high end quality player he is," Senators coach Guy Boucher said. "If you looked at his entire game, he defended unbelievably, and he makes one of those plays only a few are able to do."

The Senators caught a break when Bruins captain Zdeno Chara took a delay of game penalty for firing the puck over the glass with 12 seconds to go in regulation.

Phaneuf's goal wasn't on a power play but did come from the momentum generated off of it.

"I'm trying to keep the puck in play, but whether it was a little bounce or maybe put too much on it, those things happen," Chara said. "It was just a bad bounce and got to make sure next time to keep it in."

Boucher was proud of the character shown by his players.

"We saw our team grow throughout the year. We've developed a soul," he said. "We've also developed a capacity to overcome adversity, during games and from game to game. And that's something we did not have at the beginning of the year at all.

"I think now, the resiliency our players have displayed for two thirds of the last portion of the year came out again today. Adversity builds you or destroys you we choose to see it as a builder."

Now the Bruins will try to regain control of the momentum they have after a 2-1 series-opening win.

"We're heading back and regroup tomorrow and getting ready to play in front of our fans now," Stafford said. "We're looking forward to that."

"It's going to be a hard-fought series," added Bergeron. "Both teams erased deficits in the third period. It's going to be tough."

NOTES: Senators D Marc Methot was back in the lineup for his first game since having a finger severed by a Sidney Crosby slash on March 23. Methot's return put D Fredrik Claesson in the press box. ... The Senators also scratched RW Tommy Wingels with LW Ryan Dzingel. ... Other Senators scratches included C Chris Kelly, RW Chris Neil, C Colin White, D Ben Harpur, C Chris DiDomenico and D Jyrki Jokipakka. ... As expected, Bruins C David Krejci and D Colin Miller joined the team's injury list. Bruins D Joe Morrow replaced Miller. It was Morrow's first NHL game since Jan. 22. ... Bruins scratches were RW Jimmy Hayes and C Jakob Forsbacka Karlsson. ... Bruins recalled G Malcolm Subban from Providence for insurance, with G Anton Khudobin "dealing with a few things." Khudobin served as Tuukka Rask's backup.