Backstrom scored in overtime to make Bruce Boudreau's debut a success with a 4-3 win over the Philadelphia Flyers on Friday.
Backstrom, who also had two assists, slipped a loose puck past Philadelphia goaltender Martin Biron at 1:55 of the extra period to snap the Capitals' five-game losing streak.
"I really don't know what happened," Backstrom said. "The puck came to me and I waited out (Biron) and it worked."
Philadelphia's Mike Richards had tied the score on a rebound goal with 4:15 left in regulation.
Danny Briere and Jeff Carter also scored for the Flyers, who were outshot 35-25.
The 52-year-old Boudreau was named to the interim position Thursday, replacing Glen Hanlon, who was fired a day after the Capitals lost to the Atlanta Thrashers, 5-1. He took over a team that had lost nine of its previous 10, and 15 of 18.
Boudreau said that he wasn't really worried or thinking about his emotions before the game.
"I was really thinking about the players and trying to make sure that they were positive about themselves," Boudreau said. "They were playing such a good game that there was no way something bad was going to happen in the end."
Despite the win over the Flyers, Washington has the worst record in the league (7-14-1) and has compiled a league-low 15 points.
Boudreau said that there is a lot of work to be done but doesn't expect to make major changes.
"It's subtle changes, not like you're revamping the whole thing" he explained. "I just think the mind-set sometimes has got to change, and the culture's got to change. They've got to believe that they're really good players."
Green put the Capitals ahead with a power-play goal at 2:27 of the first period. He scored on a one-timer from the left circle after taking a cross-ice pass from Backstrom.
Clark made it 2-0 at 3:39 of the second period, streaking down the right side and scoring from the slot.
Brashear, a former Flyer, picked up his first point of the season at 14:11 of the period by deflecting Shaone Morrison's shot from the point.
The Flyers then made it close by scoring twice in a span of 2:04.
Briere hammered in a loose puck on a power play at 15:45 after Clark received a major penalty for fighting Scott Hartnell and was also called for instigation, unsportsmanlike conduct and a 10-minute misconduct.
Briere said that it is difficult to a play against a team making its first appearance under a new coach.
"Whenever you face a team playing for a new coach, their guys want to prove obviously that they can play," Briere said. "They want to show that they can do the job in certain situations. They all have a little extra jump in their legs and it showed in the first half of the game. Those guys were skating and playing hard."
Carter poked the puck between goaltender Olaf Kolzig's pads at 17:49, but the Flyers eventually paid for their slow start.
"I don't know if it was from the turkey or whatever, but we just didn't come out like we wanted to today," Hartnell said. "After the first period (coach) Johnny (Stevens) was in here yelling at us, trying to get us going."
With the addition of such free agents as Michael Nylander, Viktor Kozlov and Poti, the Capitals were expected to be a major contender in the Southeast Division this season, especially after winning their first three games.
"I approach it as the start of a new season," Kolzig said. "We're still in a deep hole and we've got a lot of work to do. It's a good start. We beat a pretty good hockey team in their own building."
Boudreau, who ran his first practice with the Capitals on Thursday morning, won the 2006 Calder Cup title with the Hershey Bears, the Capitals' American Hockey League affiliate. He also guided the Bears to the league's Eastern Conference championship and Calder Cup Finals again last season.
Coincidentally, the Bears were scheduled to play the Philadelphia Phantoms, the Flyers' AHL affiliate, on Friday night on the same Wachovia Center ice.
A third-round draft pick of Toronto in the 1975 NHL Draft, Boudreau played parts of eight seasons with the Maple Leafs and Chicago Blackhawks, recording 70 points in 141 games.
- The Flyers, who dropped all four games to Washington last season, have split two games with the Capitals this year.
- Washington LW Alex Ovechkin extended his point streak to seven consecutive games (5-3-8) with an assist on Backstrom's goal.
- Flyers LW Simon Gagne missed his seventh game in a row (concussion).