Calgary Flames backup goalie Curtis McElhinney stemmed the tide as long as he could in the third period, but T.J. Oshie of the St. Louis Blues roofed a puck into the net for the game winner in a 4-3 result on Tuesday.

Oshie's goal came at 15:02 of the third, after McElhinney had made several strong saves as St. Louis (14-12-5) applied heavy pressure in the period.

The Blues then ensured there would be no repeat of their last game, when they blew a lead late in the game to visiting Edmonton.

"I think we learned from our mistakes," Oshie said. "We talked about putting a 60-minute game together. We had our heads on straight."

McElhinney made 30 saves in his first start since Nov. 28, with Calgary outshot 10-4 in the final period.

Rene Bourque had a goal and an assist as the Flames lost their third in a row, with Daymond Langkow and Dustin Boyd also scoring.

The loss, coupled with Nashville's win, drops the Flames to sixth in the Western Conference. Calgary (19-10-4) begins a four-game homestand on Thursday against the Los Angeles Kings.

"I think we've just got to get back to our game," Boyd said. "The last three games we've shown flashes, but not enough."

David Backes and Andy McDonald each had a goal and assist for the Blues, with Alex Steen also scoring. Brad Boyes registered three assists, with Chris Mason stopping 20 shots in net.

After winning 11 of their first 15 on the road, the Flames have now dropped three straight away from Pengrowth Saddledome.

Calgary again got off to a so-so start, probably not helped by an interminable pregame ceremony for former St. Louis Blues great Brett Hull (who of course started his career with the Flames). The Blues, who've already retired Hull's number, were recognizing his recent induction into the Hockey Hall of Fame.

McElhinney's worst moment came early, when Backes one-timed a puck from just below the right circle that fooled him at the 3:56 mark of the first.

Heavy hitting started early

The Flames were doing some heavy hitting early on. Dion Phaneuf drilled Paul Kariya at centre ice, with Boyd rattling the glass with a hit on Steen.

Phaneuf helped get Calgary on the board, skating down the right side and backhanding a pass through the crease that saw its way through to Bourque for a tie game midway through the period. Bourque has scored in three of the last four games.

Nigel Dawes had a half-empty net after Mason coughed up a rebound, but the Flames forward was unable to corral the bouncing puck. Mason then denied Langkow on a chance a few minutes later.

St. Louis struck quickly on the third goal of the game. Mike Weaver headmanned the puck to Boyes at centre ice, and he spun and spotted McDonald in stride down the right wing.

McDonald blew past Robyn Regehr and roofed a shot over McElhinney at 18:51 of the first.

After allowing a total of 39 shots in the first period in the last two games, it was a better Flames showing. But Calgary last headed to the first intermission with a lead on Dec. 3, a span of seven games.

The Flames would get back on even terms with a power-play marker early in the second. Captain Jarome Iginla skated and stickhandled in the left corner to set up the goal for Langkow on the doorstep at 2:13.

The Blues had a flurry of chances in the middle of the frame. B.J. Crombeen, Kariya and Backes were among those stopped by McElhinney.

It would be Calgary taking the 3-2 lead, not St. Louis, on a play set up by Aaron Johnson. The Flames defender dumped the puck deep, and when Weaver couldn't locate it in his skates, Boyd pounced to knock in his fifth of the season.

Boyes drilled a slapper at McElhinney on a late period power play, and the Flames goalie helped preserve the lead by shutting his pads on Keith Tkachuk's rebound attempt.

Just as Flames forward Olli Jokinen was getting ready to leave the box, Boyd would take a costly hooking penalty. St. Louis kept up the pressure and worked the puck over to Steen, whose point shot got through a maze of bodies and past McElhinney.

"For 40 minutes it was a good game," Calgary coach Brent Sutter said. "We took our foot off the pedal in the third and made some mental mistakes."

Calgary's Curtis Glencross turned the puck over early in the third, forcing teammate McElhinney to make a nice glove grab on Boyes.

Kariya's backhander went off McElhinney's blocker and just wide of the left post, and the Flames goalie hugged the post to stop Boyes not long after.

Calgary's best chance didn't result in a shot, as Iginla lost control of the puck in the slot in front of Mason.

Finally, the Blues broke through. Kariya drew Calgary defenders to the left side and slipped the puck back to Oshie trailing on the right for what held up as the winner.

McElhinney gave his team a chance with a nice poke check on Steen with just two minutes to go, but the Flames couldn't capitalize.

Langkow was stopped in tight by Mason, and even with McElhinney on the bench during a Calgary power play, the score remained the same.

The Blues still have the worst home record in the West, but they improved to 6-10-2 at Scottrade Center.

"I think the [Hull] festivities definitely helped us," said Boyes. "But at the same time it was a big game. We've got to get this home record back to the way we need it, and tonight was the first step."

With files from The Associated Press