Ovechkin’s second goal, which came into an empty net at 18:12 to making it 5-3, was his 766th career goal, tying him with Jaromir Jagr for third on the NHL‘s all-time goals list.
After Elias Lindholm’s second goal with 40 seconds left got Calgary back to within one, Ovechkin had a chance for his hat trick in the waning seconds but his shot at the empty net was deflected by Lindholm.
Connor Sheary and Anthony Mantha also scored for Washington (31-18-9), which opens up its three-game Western Canada road trip with a third-straight win.
Adam Ruzicka and Oliver Kylington also scored for Calgary (34-15-7), which had its 13-game unbeaten streak snapped on home ice. The Pacific Division-leading Flames fall to 14-2-1 in their last 17 games overall.
Vitek Vanecek made 31 saves for Washington to get the win. He improves to 13-7-5.
Dan Vladar, starting for the second time in three games with Jacob Markstrom getting a night off, had 22 saves in taking the loss. He falls to 8-4-1.
Tied 2-2 after 40 minutes, Calgary took its second lead of the night at 3:45 when Kylington’s slapshot deflected off Connor McMichael’s stick and got past Vanecek.
But the Capitals tied it at 8:21 on Mantha’s goal then took the lead just over three minutes later.
Getting the puck at the sideboards, Dowd made a nice cut, to sidestep Lindholm, then from the face-off dot, ripped a shot into the top corner for his eighth goal and first in 10 games.
The Capitals also trailed 2-0 in the second, but stormed back to tie it.
McMichael was stopped on a sharp pad save by Vladar, but Milan Lucic bobbled the rebound into the slot where Sheary buried his fourth goal in as many games. Sheary has a four-game point streak (four goals, two assists).
The Capitals pulled even at 13:23 on another turnover. Sean Monahan, in front of his own net, lost the puck to Evgeny Kuznetsov and the puck went right to Ovechkin, who ripped a shot past Vladar.
Calgary took the lead halfway through the first period on a two-on-one when Lindholm took a pass across from Johnny Gaudreau and fired his 28th goal past Vanecek.
Ruzicka made it 2-0 at 8:54 of the second.