The Blackhawks will carry a 3-2 lead into Game 6 in Chicago Monday night. They rallied from a 2-1 deficit after Vancouver's Mats Sundin scored at 11:16 of the second period, and the Canucks could not score in the game's last 31 minutes.
Dustin Byfuglien scored twice, while Martin Havlat (unassisted) capped the scoring into an empty net at 18:58 of the third.
Nikolai Khabibulin made 19 saves on 21 shots for the Blackhawks, who can advance to a conference final for the first time since 1995 with a victory Monday.
Ryan Kesler and Mats Sundin scored for Vancouver.
Sundin added an assist, while goaltender Roberto Luongo was beaten three times on 29 shots for the Canucks, who suffered their second home ice loss in this series.