ST. LOUIS -- The Edmonton Oilers got the two points they needed.
Gagner ended the shootout with a goal on his first attempt of the season, giving the Oilers a full two points in the standings.
Edmonton snapped a two-game losing streak with its third victory of the season against the Blues and sixth straight in the series.
"I thought we played a gritty game," Edmonton coach Craig MacTavish said. "It was an important win. We were starting to slide the other way."
"I was just trying to be patient," Roloson said. "I stayed with them and made the plays."
Gagner beat Chris Mason with a wrist shot in the tiebreaker.
"There are a lot of moves you can use," Gagner said. "I was just trying to get him moving and it worked out well."
In the second period, Souray took a drop pass from Nilsson and whistled a wrist shot over Mason for his 13th goal of the season. It was Souray's first goal since Jan. 3 against Dallas.
"We battled for a point," Mason said. "I'd like to be a little more patient in the shootout. I think I'm flinching a half-second too early."
The Blues had two power-play opportunities in the second, but failed to score.
St. Louis finally got on the board at 5:29 of the third. With Boyes in the penalty box for interference, McClement beat Roloson high on the stick side for his eighth goal of the season. McClement has four goals in his last four games.
The short-handed goal was just the fifth for the Blues this season. They had only three short-handed goals last season.
"We had our chances but they had their chances too," McClement said. "Mason bailed us out a few times. We can't be leaving our goaltenders out to dry there."
Edmonton improved to 3-2 in shootouts, with all of the wins coming on the road. St. Louis dropped to 5-4 in shootouts.
Edmonton's Shawn Horcoff and Gilbert did not play in the third period after sustaining lower-body injuries in the second. ... Mason had the best goal-against average (1.71) and save percentage (.942) of any goalie in January. He was 3-3 during the month. ... Blues C Patrik Berglund sustained a lower-body injury early in the third period. ... Edmonton D Lubomir Visnovsky, fourth on the team with 31 points, was placed on injured reserve after dislocating his right shoulder Tuesday night against Chicago. ... Edmonton is 15-0-1 when leading after two periods.