The St. Louis Blues will try to expand their lead in the best-of-seven Western Conference quarterfinals when they host the Los Angeles Kings in Game 2 at Scottrade Center.

The fourth-seeded Blues jumped out to a 1-0 lead with an overtime win in Tuesday's opener in St. Louis. Alexander Steen scored twice, including the game-winner with 6:34 left in OT to lift the Blues to a 2-1 victory over the defending champion Kings.

The Game 1 victory already gives St. Louis more wins than it had in the entire series against Los Angeles last season. The Kings, who went 16-4 in the 2012 postseason en route to the franchise's first Stanley Cup, swept the Blues in four games of the Western Conference semifinals.

Steen scored a power-play goal in the first, and then added a short-handed tally in the extra session after Los Angeles goaltender Jonathan Quick misplayed the puck behind his own net.

Quick was pressured by Steen behind his own net and tried to play the disc off the end boards, but it bounced to the low right side, where Steen recovered it before stuffing the puck into the empty net to help the Blues draw first blood in this best-of-seven series.

"I just got on. I figured once the puck went down, I had fresh legs," Steen said. "I figured I'd try [Quick]. I guess I just got fortunate behind the net there. It hit my stick, and it went in."

Brian Elliott stopped 28-of-29 shots for the Blues, who will try to take a 2-0 lead tonight before the series shifts to Los Angeles for Games 3 and 4, on Saturday and Monday, respectively.

The reigning Conn Smythe winner Quick posted 40 saves and Justin Williams scored LA's lone goal with 31.6 ticks left in regulation to force overtime.

"It's exactly what it looked like," Quick said of Steen's goal. "I tried to make a pass. [Steen] blocked it and scored."

The Kings had won their last four overtime playoff games before suffering Tuesday's loss. L.A. also never trailed a series at any point during last year's postseason.

Steen's power-play marker just over nine minutes into the game stood as the difference for much of the contest, with Elliott turning away all comers over the first two-plus periods.

The Kings finally solved Elliott in the final minute after Quick, who made 12 saves in the third, headed to the bench for the extra attacker. Williams then took a feed from Drew Doughty and made his way into the right circle before rifling a wrister that beat Elliott high to the short side to even the score.

LA carried the momentum from Williams' goal into overtime and had a great opportunity to put the game away after St. Louis defenseman Kevin Shattenkirk caught Dustin Penner with a high stick that drew blood, resulting in a double- minor at the 12:45 mark of the extra session.

But it was the Blues who broke through, as Steen's unexpected short-handed score 41 seconds later sent St. Louis to victory.

The Blues improved to 9-4 all-time against the Kings in the playoffs.

The Kings enter this postseason as the fifth seed in the West after winning it all as a No. 8 seed last spring. This spring, L.A. is trying to become the first NHL team to win consecutive championships since Detroit pulled off the feat in 1997 and '98.

The Blues were 15-8-1 as the host during the regular season, while L.A. had a poor 8-12-4 mark on the road.

The next two battles in this series will be played in Los Angeles, with Game 3 scheduled for Saturday at the Staples Center.