With NHL scoring leader Ovechkin out with an unspecified lower-body injury, Washington failed to convert on five power plays. During their six-game skid, the Capitals have scored just seven goals, three of them by Ovechkin.
"Yeah, he's absolutely a dangerous goal scorer, leading our team and leading the league in goals," Washington's Troy Brouwer said. "We'd love to have him out there, but we don't have him right now. Even when he was in the lineup the last few games we still haven't been scoring goals."
In Ovechkin's absence, some of Washington's other offensive threats were silent. Nicklas Backstrom and Mikhail Grabovski had one shot each. Defenseman John Carlson whiffed on a promising slap shot, fired high on another and was stymied by Anderson on a breakaway.
"Their goalie played well, but we had a lot of guys with some really good looks, good chances," Washington coach Adam Oates said. "We have to score some goals. I would say the chances were good chances tonight, and we had a lot of them. It is a matter of finishing."
It was the 12th loss in the last 15 games for the Capitals, while Ottawa improved to 7-1-2 in its last 10 games to vault Washington in the Eastern Conference standings.
Turris scored his 15th of the year with just over 7 minutes left in the second period when he converted on a rush down the right side. Spezza scored his 13th goal on a power play midway through the third period, rifling a wrist shot from the left wing that went just inside the near post and past Capitals goalie Braden Holtby, who finished with 24 saves in first start since Jan. 4.
As they tried to rally, the Capitals didn't get their customary boost from their fans. The Verizon Center, which regularly sells out, was less than half full because of a snowstorm that closed schools and shut down the government Tuesday.
"It's a building where they are notorious for coming back and getting momentum," Spezza said. "So to get the two-goal lead lets us play a little different style and with a little more confidence. I thought we played better with the lead tonight in general."
It was the 32-year-old Anderson's third shutout this year and 25th in his career. He was at his best in the third period when he sprawled for a save to help the Senators kill a penalty and later kicked away a drive by Marcus Johansson.
"We played really well for 60 minutes," Anderson said. "From the start of the game to the end of the game we did things we were supposed to do."
Washington's frustration appeared to spill over late in the game when Grabovski received a 10-minute misconduct penalty during a tussle with Zack Smith.
"I want the guys to compete and be frustrated," Oates said. "But you can't live in the penalty box. We're not doing a good enough job killing penalties. So that doesn't make sense, either. But I want them to fight for everything we can."
The Capitals recalled Nate Schmidt to fortify the defense after Steve Oleksy was sent to Hershey and John Erskine sustained an upper-body injury. Schmidt, 22, opened the year in Washington, totaling six points in 28 games. ... The move came a day after Washington sent goalie Philipp Grubauer back to Hershey. The rookie had been pulled from his previous two starts. ... The Capitals play their next five games on the road.