CHICAGO -- Brent Johnson shut Chicago out for a third straight game and Pavol Demitra had the only goal Tuesday night as the St. Louis Blues beat the Blackhawks 1-0 to take a commanding 3-1 lead in their opening-round playoff series.
St. Louis, which dropped the opener of the best-of-seven series, can clinch it with a victory Thursday night in St. Louis.
Johnson tied an NHL record for most consecutive playoff shutouts, a mark held by three other goalies, most recently by Frank McCool of Toronto in 1945.
He is the first goalie to earn shutouts in his first three career playoff victories.
Johnson, in just his sixth career playoff game, made 27 saves. He nearly lost his shutout in the second period on a disputed shot by Chicago's Steve Sullivan that officials reviewed before declaring it was no goal.
The Blackhawks tried to change their luck and their look by benching Jocelyn Thibault and giving backup goalie Steve Passmore his first career playoff start. He stopped 24 shots and played brilliantly for most of two periods before Demitra beat him late in the second for his third goal of the playoffs.
Scott Mellanby maneuvered the puck from the right boards and passed across the middle to Demitra, whose low shot from between the circles beat Passmore with just 1:17 left in the second period.
The Blackhawks thought they had broken through against Johnson early in the second. Sullivan dropped a pass to Michael Nylander, whose shot went behind the net and ricocheted right to Sullivan. Sullivan's rebound shot from the right side was caught by Johnson, but it was unclear if the puck had already crossed the line when he gloved it.
In a scene reminiscent of the NFL, on-ice referee Tim Peel conferred for several minutes with officials in the video booth before declaring no goal, a ruling that set off boos at the United Center.
Sullivan had another prime scoring chance with 8:40 left on the power play when he missed a point-blank backhander.
After getting just 12 shots in Game 3, the Hawks had five in the first six minutes and outshot the Blues 10-1 in the opening period. But Johnson was again ready. He stopped a dead-on attempt by Steve Poapst and turned away two by Eric Daze, and the Blues again frustrated Chicago's power play by killing three penalties in the opening period.
Chicago finished 0-for-5 with an extra man and is 0-for-15 on the power play in the four games.
Notes: St. Louis RW Dallas Drake had to be helped from the ice with 13:42 left in the first period and did not return after receiving stitches. Drake was injured when he checked Chicago's Kyle Calder. ... Thibault was benched following a Game 3 performance when he allowed an early "soft" goal and a short-hander when he came out of the net and had his pass stolen away. ... With Lyle Odelein serving a one-game suspension for high-sticking Jamal Mayers in Game 3, and Boris Mironov out again with a groin injury, the Blackhawks turned to Chris McAlpine and Vlad Chebaturkin.