BOSTON - David Backes scored the tying goal with eighth-tenths of a second left in regulation and the St. Louis Blues went on to beat the Boston Bruins 5-4 in a shootout Monday.

Down 4-2, the Blues rallied on David Perron's power-play goal with 1:20 left. Backes then batted the puck out of the air into the net as the siren sounded. After a lengthy replay review, the goal counted.

T. J. Oshie and Brad Boyes scored in the shootout for the Blues, who have the worst record in the Western Conference and had lost nine of their previous 10 road games.

The Eastern Conference-leading Bruins trailed 2-1 before scoring three times in a span of 1:39 late in the third period.

P.J. Axelsson and Michael Ryder had power-play goals 19 seconds apart, then Zdeno Chara scored off a faceoff with 3:05 left for a 4-2 edge.

Blues reserve goaltender Chris Mason stopped Blake Wheeler and Axelsson in the shootout.

Mason kept the Bruins scoreless after replacing injured starter Manny Legace midway into the opening period until the late rally. Legace left with what the team called a lower body injury and wasn't on the bench for the remainder of the game.

St. Louis had taken a 2-1 edge when Jay McClement one-timed a shot inside the left post 6:51 into the second. There was a smattering of boos as the Blues controlled play midway into the period.

Neither team had a shot on goal until Boston made it 1-0 on Chuck Kobasew's goal 4:26 into the game.

The Blues tied it at 1 when Brad Winchester redirected Jeff Woywitka's shot from the point and the puck trickled between Tim Thomas' pads at 7:37. Thomas, on his knees, looked up to the ceiling in frustration after the puck slid behind him.

Bruins defenceman Shane Hnidy saved a goal when he reached behind Thomas and pulled out a loose puck out with his stick just before it rolled over the line in the first.

Notes: Bruins LW Milan Lucic missed his sixth straight game with an undisclosed injury and D Aaron Ward was out for his third consecutive with what the team called a charley horse sustained Jan. 13 against Montreal. Ward did leave that game, though, after being hit from behind into the boards by the Canadiens Andrei Kostitsyn. ... It was the final meeting of the teams this season. Boston beat the Blues 6-3 in St. Louis on Dec. 21. ...It was the opener of a day-night, hockey-basketball doubleheader. The Celtics were to play the Phoenix Suns at night.