OTTAWA -- Brad Marchand scored with 2:33 left in the third period to give the Boston Bruins a 2-1 win against the Ottawa Senators in Game 1 of their Eastern Conference First Round series at Canadian Tire Centre on Wednesday.
Game 2 of the best-of-7 series is here Saturday.
Frank Vatrano scored, and Tuukka Rask made 26 saves for the Bruins.
[WATCH: All Bruins vs. Senators highlights | RELATED: Complete Boston vs. Ottawa series coverage]
"They're good at keeping teams to the outside and making it a one and done," Marchand said. "We're going to have to be much better than we were tonight. We can't expect to win this series playing like that."
The winning goal came after Marchand, Patrice Bergeron and David Pastrnak had the first real sustained pressure against the Senators line of Jean-Gabriel Pageau, Tom Pyatt and Mike Hoffman. Ottawa had five opportunities to get the puck out of the zone in the sequence leading up to Marchand's goal only to be turned back by Boston.
"People in Boston have seen that shift before," Bruins coach Bruce Cassidy said. "They are pretty dynamic when they get going. Ottawa did a good job against them, let's face it. Eventually they are going to break loose.
"When [the Senators] got fatigued, you could see our guys get even hungrier. We got inside on that shift and we talked about that."
Video: BOS@OTT, Gm1: Vatrano buries wrister in playoff debut
Bobby Ryan scored, and Craig Anderson made 23 saves for the Senators.
"We had a chance to put it on somebody's stick, wait a bit, have a bit more poise, wait for the guys to be in position to make the play, but we rimmed it to nobody," Senators coach Guy Boucher said. "We threw it away. I don't think it was too cute. It was getting rid of it without looking."
Vatrano tied it 1-1 at 4:55 of the third period when his shot from the slot went in on Anderson's stick side. It was the Bruins' second shot on goal of the period after having none in the second.
"In the playoffs it's all about turning the page and focusing on your next shift," Vatrano said. "We came in after the second and knew we didn't have the best period."
Ryan scored at 10:28 of the second period to give the Senators a 1-0 lead.
Video: BOS@OTT, Gm1: Anderson stifles Chara's chance
It was the first time Ottawa allowed no shots on goal in a period in the Stanley Cup Playoffs. Their previous record was two shots, seven times.
The Bruins did not have a shot on a goal in a period once previously, against the Toronto Maple Leafs on April 6, 1939.
Goal of the game
After Erik Karlsson flipped the puck out of the Ottawa zone, Bruins defenseman Adam McQuaid had trouble handling it in the neutral zone. When it bounced behind him, Ryan darted in on the left wing and took the puck to the net, cutting across the goalmouth before scoring past Rask.
Video: BOS@OTT, Gm1: Ryan forces a turnover to open scoring
Save of the game
Rask kept the Bruins ahead 2-1 when he stopped a screened shot by Mike Hoffman with 1:09 to go in the third period.
Video: BOS@OTT, Gm1: Rask preserves lead with two late saves
Highlight of the game
After a shot by Bergeron was blocked by Dion Phaneuf, Marchand got the puck and had an open side to the left, beating Anderson.
Video: BOS@OTT, Gm1: Marchand buries blocked shot for lead
Unsung performance of the game
Bruins defenseman Charlie McAvoy played 24:11 and was plus-1 with two blocked shots in his NHL debut.
They said it
"Oh, yeah. I think if you ask [Bruins forward Riley Nash] he'll tell you he could have heard me from probably the 300s." -- Boston forward Frank Vatrano when asked if he was yelling for the puck before his goal
"That kid is a stud. He's a very, very smart player. I saw him play a couple of times this year and we're very fortunate that he was able to come in and play the way he did. A very smooth skater, smooth with the puck. For that to be his first game was pretty special. We're lucky to have him." -- Bruins forward Brad Marchand on defenseman Charlie McAvoy's NHL debut
"They outplayed us when it counted in the third period." -- Senators forward Bobby Ryan
Need to know
Bruins defenseman Colin Miller was injured at 4:52 of the second period, played one shift and then left the game. Cassidy said he will be re-evaluated Thursday. … The Bruins played without center David Krejci (upper body), and Cassidy said he is day to day. … Senators defenseman Marc Methot (finger) took the warmup but did not play. Fredrik Claesson played.
Game 2 of Eastern Conference First Round at Canadian Tire Centre on Saturday (3 p.m. ET; SN, TVA Sports, NBC)
Video: Marchand's late goal lifts Bruins to take Game 1, 2-1