WASHINGTON (AP) — Led by Jaroslav Halak's spectacular, acrobatic goaltending, the Montreal Canadiens slowed Alex Ovechkin and the rest of the Washington Capitals' high-powered offense to complete an unlikely comeback and eliminate the NHL's best regular-season team in the first round.

Halak made 41 saves, Marc-Andre Bergeron scored a 4-on-3 goal in the last 30 seconds of the opening period Wednesday night, and eighth-seeded Montreal held on to beat Washington 2-1 in Game 7, stunning the Presidents' Trophy winners by reeling off three consecutive victories.

"I'm in shock right now. I don't know what to say," Ovechkin said, his voice low, his eyes staring at the floor of the locker room. "It was great going up 3-1 in the series. But it's only one step. We didn't do it."

The Canadiens are the ninth No. 8 team to knock off a No. 1 in 32 matchups since the NHL went to its current playoff format in 1994 — and the first to come back from a 3-1 series deficit.

"Before the series started, no one gave us a chance to win, not even one game," Halak said. "We proved (to) them they were wrong."

Dominic Moore made it 2-0 for the Canadiens with 3½ minutes left, stealing the puck from defenseman Mike Green and beating goalie Semyon Varlamov. That silenced the home crowd — but the Capitals didn't go quietly.

Brooks Laich cut Washington's deficit to a goal by poking home a shot while down on his knees after Ovechkin put the puck on net off a rebound. That made it 2-1 with 2:16 left, and the Capitals kept pushing frantically forward, pulling Varlamov for an extra attacker down the stretch.

A high-sticking penalty call against Montreal defenseman Ryan O'Byrne with 1:44 to go put the Capitals on the power play. But Halak was up to the task every time, and he was helped by a remarkably high total of 41 shots that Montreal's skaters were credited with blocking.

Halak's teammates piled on him at the final horn, while Ovechkin skated all alone toward the other end of the ice, his stick resting on his knees, and his head bowed. The league's two-time MVP has played in four career playoff series, and each has gone to a Game 7. The Capitals are 1-3 in those deciding contests.

"I thought we had a good chance to win the Stanley Cup this year," Washington coach Bruce Boudreau said, "and I would have bet my house that they wouldn't have beaten us three games in a row and we would have only scored three goals in almost 140 shots."

Montreal moves on to face Sidney Crosby and the defending Stanley Cup champion Penguins in the second round, with Game 1 at Pittsburgh on Friday. The fourth-seeded Penguins were the only higher-seeded team to win a first-round series in the Eastern Conference.

Yes, that's right: All three division champions in the East are done already — Washington, New Jersey and Buffalo.

All in all, this series represents a monumental collapse by Washington, which earned a third straight Southeast Division title, compiled the league's best record for the first time and led the NHL in goals.

This is also a club that preceded each home game against Montreal with a video display that included an image of the Stanley Cup and the words, "NOTHING ELSE MATTERS," while the Metallica song of that name blared.

The Capitals owned the best home record in the NHL during the regular season, but lost Games 1, 5 and 7 in Washington.

The Canadiens allowed more goals than they scored this season and qualified for the playoffs on the final weekend, but Halak was on their side.

He was yanked during Game 3 in favor of Carey Price, who also started Game 4. But Montreal coach Jacques Martin went back to Halak for Game 5 — a switch that worked out rather well. Halak made 37 saves in a 2-1 win in Game 4, 53 saves in a masterpiece of a 4-1 victory in Game 5, and then produced more of the same Wednesday. All told, Halak stopped 131 of 134 shots in the last three games.

And it was fitting that the series ended with an unsuccessful Capitals power play. They led the league in that category in the regular season by converting on 25 percent of man-advantage chances, but went only 1 for 33 against Montreal.

It was the Canadiens who scored on a power play with 29.1 seconds left in the first period, set up by a cross-checking penalty on Green, a finalist for the Norris Trophy as the league's top defenseman. Bergeron — a defenseman on the ice for only 1:25 in the period, less than any other player — took a cross-ice pass from Scott Gomez and, all alone at the top of the right circle, let fly a slap shot as he dropped to a knee.

Holding that lead, the Canadiens were often content to focus on defense, and they recorded only three shots in the second period. Overall, Montreal was outshot 42-16.

All of 24 seconds into the third period, Ovechkin put the puck past Halak on a shot from the left circle, but the goal immediately was waved off by an official because Washington forward Mike Knuble was in the crease, backing into Halak.

The Capitals — and their red-clad, flag-waving fans — did not realize at first the apparent goal did not count. Ovechkin did his customary slamming into the glass to celebrate, and his teammates mobbed him, while the crowd roared. But the call was announced, leaving Boudreau leaning over the boards, gesticulating and yelling, while spectators yelled full-throated insults at the official.

"It's a pretty tough one to take," Boudreau said after watching replays of the play. "I don't know how they could make the call."

Later in the third period, Montreal's Maxim Lapierre slammed into Varlamov in the crease, forcing the goalie and the puck into the net. There was no goal — and, to Washington's frustration, no penalty, either.

NOTES: Washington's Alexander Semin, who scored 40 goals this season, wasted a great chance in the first period and finished the series without a goal. ... It's the second time Montreal won a series after trailing 3-1.