Bruins coach Claude Julien complained that his team wasn’t winning the battles that are determined by effort.

“The proof is the overtime goal,’’ he said. “We win the draw; they outmuscle us to get the puck, they get a good second effort to get into the scoring area and score a goal.’’

A 22-year-old veteran of just 21 NHL games, Holtby moved into the Capitals’ lineup because of injuries to Tomas Vokoun and Michal Neuvirth. Holtby played in only seven games this season, but he started five of Washington’s final 10 games.

In the playoffs, he has allowed two goals in more than 144 playoff minutes, matching the reigning Vezina and Conn Smythe Trophy winner across the ice.

“He is playing great right now,’’ Ovechkin said. “We just hope he can continue. This kid can save us and keep us in the game in overtime.’’

Backstrom missed most of three months with a concussion before returning March 31. Coach Dale Hunter said the Swede wasn’t yet at full strength, but he’s getting better and will see more ice time as the playoffs go on.

Backstrom absorbed a two-handed shove from Thomas in the third period when he was swiping at a covered puck in the crease.

“Well,’’ Backstrom said, “today I got the last laugh.’’

The first game remained scoreless into overtime, when Chris Kelly scored after 1:18 to give the Bruins the edge in the best-of-seven series. The defenses dominated again Saturday, though each team did manage to break through once in regulation.

The Capitals took their first lead of the series when Brouwer poked a puck out of the crease and under Thomas, who was blocked by Bruins defenseman Greg Zanon. That ended Thomas’s postseason shutout streak at 161:41 — a span that included shutouts in Game 7 of the Stanley Cup finals and Game 1 of this series.