Matt Niskanen, Jakub Vrana and Michal Kempny also scored for the Capitals (22-10-3). Washington is 7-1-0 in its past eight games and has scored at least four goals in 10 of its past 13.
Mike McKenna stopped 29 shots in place of the injured Craig Anderson.
Copley is the first rookie goalie to blank the Senators since James Reimer in 2011.
“The guys did a great job blocking shots and denying them great chances,” said Copley. “It was a real good team win.”
The score was hardly flattering to the Senators, but coach Guy Boucher wasn’t too disappointed by the effort.
“It wasn’t a 4-0 game, that’s for sure,” Boucher said. “We played really well and had so many scoring chances and their goalie stoned us.”
Washington took a 3-0 lead midway through the second when Vrana stole the puck from Mark Stone and beat McKenna with a flashy move. Kempny made it 4-0 at the 13-minute mark when his point shot deflected off Cody Ceci.
The Senators trailed 2-0 after the first period, but it could have been more if it wasn’t for McKenna.
Connolly opened the scoring at 1:32 when he redirected Jonas Siegenthaler’s point shot.
“When we’re ahead in games we’re definitely better,” Connolly said. “We know when we’re behind we have a lot of guys that can hurt you as well, but when we get the first one we settle in and definitely on a back-to-back it makes it easier so it was good to get that first one.”
McKenna made impressive glove saves on Andre Burakovsky and Travis Boyd. Bobby Ryan also stopped a sure goal when McKenna was caught out of position.
The Capitals took a two-goal lead late in the period when Niskanen got behind Ceci and tipped Nicklas Backstrom’s pass for his fifth of the season.
NOTES: With Anderson dealing with an upper-body injury, Marcus Hogberg was recalled from the American Hockey League’s Belleville Senators. … The Senators honored LPGA golfer and Smiths Falls, Ontario, native Brooke Henderson prior to the game and had her drop the puck. … Ottawa’s Tom Pyatt and Max Lajoie were healthy scratches. … Washington’s Tyler Lewington made his NHL debut Saturday night.
Capitals: Host Carolina on Thursday night.
Senators: Play at the New York Islanders on Friday night.
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