The Blackhawks can finish off the best-of-seven National Hockey League Western Conference finals at home on Sunday.
Patrick Marleau scored twice for the Sharks, the second straight game in which he has scored San Jose’s only two goals.
The teams exchanged goals late in the third period. Dave Bolland scored on a breakaway with 6:55 remaining to give the Blackhawks a 2-1 lead, only to have Marleau score his second goal of the game with 4:23 left to force overtime.
After a scoreless first period, Marleau had a power-play goal early in the second period and Chicago’s Patrick Sharp tied the game three minutes later.