Jake Allen made 18 saves for the Blues (6-7-3), who have lost two in a row and are 2-3-0 in their past five games. They defeated the Blackhawks 7-3 in St. Louis on Oct. 27 to start Chicago's 0-6-2 slide.
"I thought Jake, he played a great game for us," Blues forward Tyler Bozak said. "Gave us a really good chance to win. It's funny, we've been scoring tons of goals and giving up a lot, and then we can't score and we only gave up one. So it's a tough loss. I thought we did a lot of good things. We have to get back to work tomorrow."
Seabrook scored on the power play to give the Blackhawks a 1-0 lead at 4:05 of the second period. Allen made the save on Seabrook's shot from the bottom of the left face-off circle, but the rebound went in off Blues defenseman Jay Bouwmeester's right skate in the crease.
"It's a good feeling," Seabrook said. "It was nice to hear some music when they came in here after the game tonight. I think the boys are all fired up. The way we played, I think, going into the second period, being able to score a goal, hold on to the lead ... I think the way everybody played, everybody stuck with it. Everybody stuck with the game plan. Everybody worked hard."