The Blues tied the game at 1-1 with an equally awkward goal 31 seconds later. Roy one-touched the puck from the top of the left circle toward the net. The puck fluttered a little bit, but stayed along the ice as it went past Bruins defenseman Johnny Boychuk and Blues forward Chris Stewart, who were battling at the left dot, and slid through Rask's five-hole before the goaltender could get his stick down.
The Bruins outshot the Blues 10-8 in the period.
St. Louis grabbed its first lead with 5:56 remaining in the second period. David Backes won a draw at the right dot and then went to the net, where he joined teammate Alexander Steen. Kevin Shattenkirk's shot from the point went off Backes' stick and past Rask for a 2-1 Blues edge.
Carl Soderberg made sure the teams went to the second intermission tied again. Chris Kelly sent the puck from behind the net to Soderberg at the top of the right circle, and then Soderberg's wrist shot went through Kelly's screen and over Halak at 18:41.
The Blues have won their past six games in Boston. The Bruins have not won against St. Louis at TD Garden since Jan. 30, 2001.
The Bruins, who just returned from a 2-1-0 road trip, will remain home for games against the Carolina Hurricanes (Saturday) and Pittsburgh Penguins. With their road trip completed, the Blues will be home Saturday against the Dallas Stars.
FLYERS 4, SABRES 1: In Philadelphia, Matt Read scored a pair of goals to lead Philadelphia to its fifth win in six games.
Vincent Lecavalier also scored and Scott Hartnell added an empty-net goal for the Flyers, who set a season-high with 46 shots.
Read's goals came 1:40 apart late in the second period. Steve Downie and Sean Couturier assisted on both tallies for Philadelphia (9-10-2), which outshot Buffalo 46-30.
Tyler Myers netted the lone goal for Buffalo, which is 1-3 under interim coach Ted Nolan and an NHL-worst 5-18-1 this season.
The game was the first between two First Nations head coaches. Nolan is Ojibwe, and from Sault Ste. Marie, Ontario, and Flyers coach Craig Berube is part-Cree and from Calahoo, Alberta.
Myers beat Ray Emery from close range in the first period to stake Buffalo to a 1-0 lead. But Read tied it with a one-timer from the slot with 6:51 left in the second.
PREDATORS 4, LEAFS 2: In Toronto, Craig Smith scored two goals, and Marek Mazanec made 24 saves at Air Canada Centre.
Smith's power-play goal, the Predators' second of the night, at 16:25 of the second period gave them a 3-1 lead. His goal early in the third period, his sixth of the season, made it 4-1.
The Maple Leafs scored first when Peter Holland skated into the offensive zone and fired a wrist shot past Mazanec at 5:48 of the first period. It was Holland's second goal of the season, his first for the Maple Leafs after arriving in a trade from the Anaheim Ducks on Saturday.