Clowe went 21 games without scoring, matching his longest drought.
"I just got a pat on the back and a 'Good job' from the coach," Clowe said. "It was nice to see the other guys on the ice because they were more excited than I was."
Dany Heatley added his ninth goal of the season. The Sharks have won four straight and six of their last seven games. They are 9-4-1 overall and 4-0-1 at home.
"That's how you have to beat [Craig] Anderson," Sharks coach Todd McLellan said. "You're not going to beat him on the first or second. You have to get him out of position and find the open net."
Anderson stopped 43 shots, and Matt Duchene scored for the Avalanche (10-2-2). Colorado had won four straight and earned points in its last 10 games (8-0-2).
"It was one of those nights where they were throwing everything at the net; lots of bodies there," Anderson said. "We were right there the whole time but they have a great team over there and they know how to score. They took it to us."
Anderson continually turned away the Sharks in the first two periods, making 31 saves before Clowe scored with 6 seconds left in the second. Anderson stopped shots by Patrick Marleau and Rob Blake before Clowe slipped it past.
"When you're getting that many shots on the net you feel good about yourself and the team," Clowe said. "It was only frustrating because they had us pinned down for a couple of minutes before we scored."
Heatley redirected a pass from Jason Demers early in the third period.
"We were fortunate to be in that game," Colorado coach Joe Sacco said. "San Jose came out and played extremely hard. You can't let them, with all their firepower, spend a lot of time in your end."
Duchene scored a short-handed goal to make it 2-1, but McGinn knocked in a rebound 30 seconds later.
"That was huge because we kind of dropped it there when we gave up the short-handed goal," McGinn said. "It was good to get it right back and put the pressure back on them."
Anderson took responsibility for the quick score.
"It's my job to stop them no matter what and I didn't and they put the game out of reach," he said. "Give him credit; it was a nice shot."
Avalanche left wing T.J. Galiardi was sent to Denver to have his injured right ankle examined. ... Sharks center Joe Thornton took his first penalty of the season, an interference call late in the second period. ... Colorado defenseman John-Michael Liles returned to the ice after missing seven games because of a bruised right shoulder. ... The Sharks are 1 for 19 on the power play at home. ... Avalanche center Matt Hendricks was placed on the injured reserve list and center Philippe Dupuis was recalled from Lake Erie. ... Sharks defenseman Dan Boyle's points streak was snapped at nine games.
Copyright by STATS LLC and The Associated Press
Arena: SAP Center Location: San Jose, California
Referees: Kerry Fraser, Stephen Walkom Linesmen: Vaughan Rody, Mark Wheler
Attendance: 17,562 (100.4% full)
Team Stat Comparison
Power Play Goals
Power Play Opportunities
Shots on Goal
No scoring this period
Ryane Clowe (1)
Assists: Patrick Marleau, Rob Blake
Dany Heatley (9)
Assists: Jason Demers, Ryane Clowe