Rene Bourque committed a holding penalty in the game's first minute, giving Alex Ovechkin and the Washington Capitals enough momentum to last the entire game.
In the third period of the losing cause, Bourque lifted his right elbow into the head of Nicklas Backstrom, who had earned assists on all three Capitals goals.
"The puck isn't even close," Capitals centre Marcus Johansson said. "And it's very, very unnecessary."
Bourque went to the penalty box for elbowing, while Backstrom stayed in the game for two more shifts but didn't finish Washington's 3-1 win over the Calgary Flames on Tuesday night.
"It was precautionary, and he's getting evaluated," Washington coach Dale Hunter said of Backstrom, the team's points leader with 42 points. "We'll know more [Wednesday]."
Bourque mischievous deeds put a bookend on the Capitals' fourth straight win and the Flames' fourth straight loss. Ovechkin and Troy Brouwer scored power-play goals, Dennis Wideman added a goal, and Tomas Vokoun made 18 saves for the Capitals, who improved to 9-6-1 under coach Dale Hunter.
Other stats told a more complete story of how the Capitals are evolving under Hunter after the middling start that got Bruce Boudreau fired. Washington blocked a season-high 24 shots, won 63 per cent of its faceoffs and didn't allow a power-play goal for the ninth straight home game. Vokoun has stopped 125 of the last 131 shots he has faced, and the team is allowing only 2.25 goals per game since Hunter replaced Boudreau in late November.
"This is too good [of a] group to be in the middle, middle of nowhere," said Ovechkin, who has seven goals in seven games. "We just want to be in the playoffs."
Bourque's reviews weren't as good. Calgary coach Brent Sutter said a team can't "take a penalty 200 feet from the net" on the first shift of the game against a team like the Capitals. Ovechkin's one-timer soon made the score 1-0, his 17th goal of the season.
"I just felt like I was stuck in the boards, and even though it looked like I was holding him, I couldn't really move because my arm was on the other side of him," Bourque said. "But, yeah, it's a back-breaker. They scored right away in the first minute, and ... I take a stupid penalty."
Bourque was more nebulous about his hit on Backstrom. Bourque was suspended two games last month for a hit on Brent Seabrook of the Chicago Blackhawks, and this one could lead to more time off the ice.
"Did it look really bad? Was he hurt? I didn't even know if I clipped him," Bourque said. "I didn't even know if I hit him in the head."
Curtis Glencross had the lone goal for the Flames, who have one game left on a seven-game trip. Miikka Kiprusoff made 18 saves, and Jarome Iginla remained one goal shy of becoming the 42nd NHL player to score 500.
The Capitals got another boost with the return of defenceman Mike Green, who had missed 23 straight games and 29 of 30 with a sprained right ankle and then a groin injury. Yet while Green was back, forward Alexander Semin was out — listed as day-to-day with an undisclosed upper body injury.