CHICAGO -- The St. Louis Blues were surging even before their power play started to click.
Paul Kariya had the Blues' other power-play goal as St. Louis, which entered the game 2-for-21 on the power play, converted two of three attempts against Chicago.
The goal was Kariya's first of the season and first since signing with the Blues as a free agent last summer. Bryce Salvador scored at even strength for the Blues (4-1). Brad Boyes earned two assists by setting up Kariya's and Tkachuk's goals.
"I think we moved the puck well on the power play," Kariya said. "It's something we have to build on. We're off to a good start and that's important."
Added Tkachuk: "The power play was something we were concerned about, but it came through."
Blues coach Andy Murray said assistant coach Ray Bennett worked with the Blues' power-play units to make changes for Wednesday's game.
"Ray Bennett did a good job of preparing the power play," Murray said. "He had some ideas and they worked. Good players made good plays. When guys execute, they make coaches look better."
Jason Williams scored Chicago's lone goal, a fluke power-play score that stood up to a video review.
Nikolai Khabibulin made 23 saves for the Blackhawks (3-3), who fell behind 2-0 in the opening 6:31.
"We were down 2-0 fast and that was the game right there," Chicago defenseman Duncan Keith said.
"In this league, when you have a poor start, it's tough to come back every night," Blackhawks coach Denis Savard said. "There was effort and a lot of good things happened, but once you get down 2-nothing, it's tough to come back."
In each of the Blackhawks' three victories this season, they've rallied late.
Kariya opened the scoring on a power play 2:14 into the game. Kariya, who had six assists in St. Louis' previous four games, beat Khabibulin high on the glove side after taking a cross-ice pass from Boyes.
Salvador made it 2-0 at 6:31 on a shot from the left circle that sailed over Khabibulin's right shoulder.
Williams' power-play goal made it 2-1 with 6:20 left in the period. His shot bounced off the back boards and landed on top of the St. Louis net. The puck rolled back over the crossbar and crossed the goal line before Legace knocked it out.
Play continued for another 1:08 before the next whistle. During the stoppage, referee Dan O'Halloran asked the NHL office in Toronto to review the play. After the goal was awarded, the clock was rolled back to the time the puck went in at 13:40.
Tkachuk made it 3-1 with a power-play goal at 5:17 of the second. Alone in front to the net, he tucked a feed from Boyes between Khabibulin's pads.
- The Blackhawks announced that RW Martin Havlat wouldn't undergo surgery to repair an injured right shoulder. Havlat, injured in Minnesota during Chicago's season opener, will miss four to six weeks.
- Chicago LW Rene Bourque sat out due to a groin stain. He is day to day.
- Kariya has points in each of the Blues' first five games.
- St. Louis D Erik Johnson missed his third game because of a fractured foot.
- Blues D Eric Brewer is also out with a shoulder injury.