The Capitals outshot the Sharks 14-6 in the second.
"I think there have been a lot of games throughout the year where they are one-goal games and we just can't seem to find the back of the net," Washington forward Connor McMichael said. "Tonight, I think we outchanced them pretty heavily. We had a lot of great looks. We just couldn't put the puck in the net."
San Jose played without top-line center Tomas Hertl, who sustained a mid-body injury during a day off Sunday. He is expected to be on the upcoming road trip.
"Obviously Tommy's a pretty irreplaceable guy in our group," Kunin said. "He was missed for sure, but everyone kind of stepped up in his absence and found a way to get the win."
NOTES: Sharks center Nico Sturm won 14 of 17 face-offs (82.4 percent). … Capitals forward Alex Ovechkin was held without a point and remains three shy of 1,500 in his NHL career. He had five shots on goal in 22:02 of ice time. … Washington plays a back-to-back at the Los Angeles Kings and Anaheim Ducks on Wednesday and Thursday, respectively.