Zednik was recently demoted recently to Washington's fourth line, but it was that trio that connected with 4:06 left in the second period to break a 1-1 tie and give the Capitals a lead they wouldn't relinquish. Gritty work along the end boards by Donald Brashear and Boyd Gordon helped work the puck free to Zednik behind the Flames net, where he fended off defenceman Andrew Ference and curled out in front, squeezing a shot through the pads of Miikka Kiprusoff.
Zednik scored the eventual game winner at 10:27 of the third when Alexander Ovechkin's pass sent him in on a breakaway and he snapped a shot past Kiprusoff, making it 3-1.
Jarome Iginla scored on a breakaway less than two minutes later to get the Flames back to within one, but Calgary could not get the tying goal past Olaf Kolzig, who finished the night with 38 saves.
Dainius Zubrus also scored two for Washington (4-3-4), including an empty netter with 19 seconds left. Ovechkin had two assists.
The Capitals picked up five of eight points on their four-game trek through the Northwest Division and have lost just twice in regulation in their last 10 games (4-2-4).
Kristian Huselius scored the other goal for Calgary (3-6-1). The struggling Flames are 1-4-1 in their last six games and are tied with Columbus for 13th spot in the Western Conference, just one point ahead of the last place Phoenix Coyotes. The Flames head onto the road for three games beginning Wednesday in Detroit.
The game was scoreless until Huselius put Calgary ahead at 6:50 of the second period.
Iginla crossed the Washington blue-line and dropped the puck to Huselius, who patiently wove his way into the middle of the high slot before releasing a rising shot that eluded Kolzig through a screen.
However, Zubrus answered back with his sixth of the year on a power-play just 73 seconds later.
Kiprusoff couldn't control a rebound on a shot from the point and after defencemen Andrei Zyuzin and Robyn Regehr both failed to clear the bouncing puck, Zubrus swooped in and tucked the puck behind the Flames goaltender.
Kiprusoff made 27 saves, dropping to 3-6-1. Kiprusoff has played every minute of Calgary's games this season.
Notes: Calgary D Dion Phaneuf returned to the lineup after missing one game with the flu. . . . Washington C Rico Fata and D Steve Eminger were both healthy scratches for the first time on the season. . . . The Flames were the last NHL opponent for Ovechkin to face. . . . Washington's final 71 games will all take place in the Eastern time zone. . . . With eight goals, Washington LW Alexander Semin is only two short of matching the 10 goals he scored in 52 games as a rookie in 2003-04. Semin played in Russia last season.