ST. LOUIS — Duncan Keith and the Chicago Blackhawks did their part to spoil the St. Louis' playoff chances.

The star defenceman scored a power-play goal with 8.5 seconds left and the Blackhawks beat St. Louis 4-3 on Wednesday night.

The result meant the Los Angeles Kings clinched a playoff spot.

Alex DeBrincat had a goal and an assist, Andreas Martinsen and Blake Hillman also scored, and Jean-Francois Berube made 30 saves. The Blackhawks beat the Blues for the first time in three meetings this season.

"We're trying to win the game," Keith said. "At the end of the day, it's a bigger game for them but I thought we did a good job of matching their intensity and for us it's fun to play in a game like that. ... There was something on the line so it was a little easier to get the fire going little bit."

Vladimir Tarasenko and Brayden Schenn each had a goal and an assist for the Blues. They have lost four straight to fall a point behind idle Colorado for the second wild-card spot in the Western Conference.

Robert Bortuzzo also scored for the Blues, and Jake Allen made 22 saves in his 14th straight start.

"We played terrible in the third from myself out," Allen said. "It's unacceptable especially at home against a team that really has nothing to play for except beat us."

Hillman scored a short-handed goal, his first in the NHL, midway through the second to cut the Blues' lead to 3-2. He is the fifth Blackhawk to score their first career goal this season.

"It's probably the hardest one-timer I've ever taken in my life," said Hillman, who was playing in his second NHL game. "I closed my eyes and it went through a couple of bodies and luckily Allen didn't see it."

DeBrincat tied it at 3 at 8:30 of the third with an unassisted goal, before Keith found the net for the first time in 22 games.

"It's been awhile since he scored obviously, but we did some good things as the game progressed and drew the penalty and got a break," Blackhawks coach Joel Quenneville said.

Bortuzzo opened the scoring at 4:16 of the first period with his fourth goal of the season.

Martinsen tied it for Chicago at 8:57 with his first goal of the season, firing a wrist shot that trickled between Allen's legs after the Blues failed to clear the puck twice.

Schenn regained the lead for the Blues just 47 seconds into the second period, putting home a rebound from Vince Dunn's shot from the high slot. Schenn's 27th goal is a career high.

Tarasenko made it 3-1 at 5:44 of the second. St. Louis took advantage of a Chicago defensive line change and Schenn sprung Tarasenko for a breakaway.

FANCY STICK WORK

Just 52 seconds into the game, Jaden Schwartz had a wrap-around attempt into a wide-open net, but Keith got his stick on the goal line to block the puck until Berube could get his glove down. The play was reviewed and it was determined that the puck did not cross the line.

"I just tried to do what I could there to get everything I could, all the pressure on my stick, because I knew he had some momentum coming around there and was trying to wrap it around, the lane wasn't there," Keith said. "A little luck too in that regard, but Berube ended up getting over there and taking the pressure off."

NOTES: Blues D Alex Pietrangelo played in his 615th career game, one shy of Bob Plager for second-most by a defenceman in franchise history. ... The Blackhawks will honour Hall of Famer Stan Mikita before Friday night's home game against the Blues. Mikita's grandsons will take the ice on his behalf during the national anthem and highlights of Mikita's career will be played. ... Blues prospect G Ville Husso (San Antonio) was named to the 2017-2018 AHL All-Rookie team. ... Blackhawks prospect D Adam Clendening was selected as the CCM/AHL Player of the Week after scoring two goals and five assists for the week ending April 2.

UP NEXT

The teams will meet again Friday night in Chicago.