Antti Niemi stopped Marian Hossa's shot from the top of the right circle, but kicked the puck toward the goal line. Sharp swooped in to bury the rebound for his 16th goal of the season, and second overtime winner in the Blackhawks' last two games.
More On The Blackhawks
For all the latest on the Blackhawks, check out Scott Powers' blog on ESPNChicago.com. Blog
Sharp, who also connected in the extra period Thursday night in Chicago's 3-2 victory over the New York Islanders, has six goals in his last six games and nine in his last eight.
"We stole it in overtime," Sharp said. "It wasn't the prettiest game, but it's what we'll have to do down the stretch the rest of the way -- win games like that, find a way to win the ugly ones."
Sharp, who helped Chicago improve to 4-0-1 in its last five, was dizzy from an eventful week. His wife, Abby, gave birth to the couple's first child, Madelyn Grace, on Friday.
"It was a pretty emotional goal," Sharp said. "It was tough to focus on hockey with so much going on back home. We have a great locker room. It's pretty easy to turn things off when you come to the rink, but I was space cadet the whole game."
Chicago's Andrew Brunette scored on deflection with 1:06 left in the third period and Blackhawks goalie Ray Emery pulled for an extra attacker to tie it 2. Following a Chicago timeout -- and after Jonathan Toews won a faceoff in the Sharks' zone -- Brunette tipped in Hossa's shot from the top of the slot.
"It was a big win on the draw, made the play happen," Toews said. "It was a good way to get back in the game."
"We played against a very good team and did very well for two periods," San Jose coach Todd McLellan said. "It was pretty evident that one team have played three games in four nights and the other was fresh.
"We ran out of gas a little bit in the third and we lost a number of key faceoffs in the third period that allowed them to start with the puck and play in our end. That's was a concern of ours, as well as obviously on the tying goal."
Emery started a second straight game for the first time this season and made 35 saves. He has appeared in Chicago's last four contests -- making three starts and one relief appearance -- while No. 1 goalie Corey Crawford has struggled.
"You feel better the more you play," Emery said. "Even though they threw a lot of pucks at me, I think I did a good job of sorting things out, not giving them second chances."
Niemi stopped 31 shots and was sharp for the second time this season against his former teammates. Niemi, who backstopped the Blackhawks to the Stanley Cup in 2010, shut out Chicago 1-0 in the teams' only previous game this season on Nov. 23 in San Jose.
"(Niemi) is a competitive guy and I know he has a lot of really good friends on the other side of the building he likes to compete against," McLellan said. "He's had some very good nights against this team."
Niemi made several close-in saves in the first to keep it scoreless. McGinn eventually scored the only goal of the first with 3:35 left, thanks to a Chicago defensive breakdown.
San Jose's Michal Handzus slid the puck to McGinn, left wide open by Chicago defenseman Niklas Hjalmarsson at the right edge of the crease. Emery made a pad save on McGinn's first attempt, then got a piece of McGinn's first rebound try before the forward knocked in the loose puck.
The Sharks dominated the second period, outshooting Chicago 16-5, but led just 2-1 after 40 minutes. Kruger was credited with a goal that tied it at 7:53 of the second. Hjalmarsson's shot from the point struck Kruger, then hit the right post and clanked into the net.
Braun put San Jose back in front just under 2 minutes later on a screened shot from the top of the right circle.
Niemi stopped Hossa with a spectacular kick save during a Chicago power play 5:20 into the third to keep the Sharks ahead.
Late in the period, Niemi blocked an attempt by Dave Bolland from the edge of the crease and a point-blank screened backhander by Hossa. But Brunette eventually tied it at 2. Emery made a tough glove save on Brent Burns with 3:30 into overtime.
Chicago D Brent Seabrook played his 500th NHL game. ... San Jose placed D Douglas Murray (right hand) on injured reserve and recalled D Matthew Irwin from Worcester of the AHL. Murray has missed four games. Irwin did not play Sunday. ... Sharks D Jim Vandermeer missed his third game because of an upper-body injury. ... Blackhawks LW Bryan Bickell was a healthy scratch for the fifth straight game .... Former Blackhawks defensemen Chris Chelios and Gary Suter, who will be inducted in to the U.S. Hockey Hall of Fame in a ceremony in Chicago on Monday, were present at the game. Other inductees present were retired forward Keith Tkachuk (Winnipeg, Phoenix, St. Louis and Atlanta) and broadcaster Mike "Doc" Emrick.
Copyright by STATS LLC and The Associated Press
Arena: United Center Location: Chicago, Illinois
Referees: Stephen Walkom, Francis Charron Linesmen: Thor Nelson, Anthony Sericolo
Attendance: 21,456 (108.8% full)
Team Stat Comparison
Power Play Goals
Power Play Opportunities
Shots on Goal
Jamie McGinn (6)
Assists: Michal Handzus, Dan Boyle
Marcus Kruger (3)
Assists: Niklas Hjalmarsson, Nick Leddy
Justin Braun (1)
Assists: Brad Winchester, Andrew Desjardins
Andrew Brunette (7)
Assists: Marian Hossa, Duncan Keith
Patrick Sharp (16)
Assists: Marian Hossa, Brent Seabrook