Duncan Keith, Ben Eager, Bryan Bickell and Kris Versteeg scored in a 3:08 span in the first period and the Blackhawks held on to beat the Blues 6-5 on Wednesday night for their fifth straight victory.
Versteeg added three assists to set a career high for points in a game and become the first Chicago player to have a four-point game since Dec. 28, 2008.
After the Blackhawks built a 6-1 lead midway through the second period, they nearly blew it against the Blues, who got goals from David Perron, Roman Polak, Brad Winchester, T.J. Oshie and Brad Boyes. Boyes completed the scoring on a penalty shot with 30.9 seconds left in the third.
"Throughout the first and second periods, we came out strong," Versteeg said. "Maybe there was a bit of fatigue, but that's definitely not the way we want to finish off."
"In the first 40 minutes, we were in good shape," Chicago coach Joel Quenneville added. "In the third period, we took our foot off the gas and almost gave it away."
St. Louis nearly came back despite playing its first game after being eliminated from playoff contention Tuesday night when Colorado beat Vancouver.
The Blues also absorbed an emotional hit when forward Keith Tkachuk announced his retirement before the game. The 38-year-old Tkachuk played his 1,200th game Monday night, but was scratched Wednesday night because of a lower-body injury. He will play his final home game Friday night.
"If anything, he gives us more to play for," St. Louis forward David Backes said. "He was a warrior for 19 years in this league.
"It was almost semi-disrespectful that the night he says he's going to retire that we put the sort of effort we did in the first half of the game."
Blackhawks forward Marian Hossa left the game after one shift in the second period because of an unknown injury. Hossa appeared to have sustained the injury after being hit and knocked to the ice by Winchester at 8:07 of the first. Hossa played several shifts after the incident.
After the game, Quenneville said the injury wasn't serious.
Chicago goalie Antti Niemi made 26 saves in his seventh straight start and 10th in the last 11 games.
Perron opened the scoring 4:22 in with 20th goal, scoring on rebound when he was left open at the edge of the crease.
Then the Blackhawks scored four goals on six shots in just over 3 minutes.
"They skated and we watched," Backes said. "It was almost like figure skating at the Olympics. We were the spectators in the stands and they were skating all over the ice."
Keith tied it at 1 at 6:17 when he pinched into the left circle and completed a give-and-go with Versteeg during a 4-on-4.
Just under a minute later, Eager banged in a loose puck from the crease to make it 2-1. Bickell scored 30 seconds later and sent Mason to the bench when his screened 45-foot shot from the left boards sailed over Mason's glove into the top corner.
Versteeg's short-handed goal at 9:25 capped the flurry. He scored from the slot after moving 2-on-none with Patrick Sharp and taking Sharp's feed.
Ladd stretched it to 5-1 at 5:54 of the second on wrist shot from the left circle. Hendry made it 6-1 midway through the second, before Polak cut it to 6-2 with 4:08 left in the period. Winchester was credited with a tip-in at 3:43 of the third to make it 6-3, and Oshie trimmed it to 6-4 with 6:16 remaining.
Boyes closed it to 6-5 on his penalty shot, awarded after he was hacked by Chicago's Dustin Byfuglien on a breakaway.
Hossa has 24 goals and 26 assists in 50 games this season. He missed the Blackhawks' first 22 games following offseason shoulder surgery. ... The Blackhawks recalled Bickell from Rockford of the AHL on Wednesday. ... Chicago RW Tomas Kopecky sat out with an upper-body injury, as did D Kim Johnsson who missed his 13th game. RW missed Troy Brouwer missed his second straight game due to personal reasons. St. Louis D Barret Jackman and C Patrik Berglund sat out with upper-body injuries.