ST. LOUIS -- Mattias Janmark and Vernon Fiddler scored 20 seconds apart and Kari Lehtonen stopped 35 of 37 shots to lead the Dallas Stars to a 3-2 victory over the St. Louis Blues Monday night in Game 6 of their second-round playoff series.

The win tied the series at three games each and forces a deciding Game 7 Wednesday night in Dallas for the right to advance to the Western Conference final.

The Blues have not played in the conference final since 2001 while the Stars' last reached that round in 2008. The Blues will be playing their second game seven in this year's playoffs, having eliminated the defending Stanley Cup champion Chicago Blackhawks in round one.

Trailing 3-0 after the first period, the Blues scored once in the second period and then cut the lead to 3-2 on a goal by Patrik Berglund off a pass from Jori Lehtera at 8:59 of the third period.

The Blues pulled goalie Jake Allen with 1:48 to go for an extra attacker but could not beat Lehtonen for the tying goal.

The Blues outshot the Stars 37 to 14 in the game, including a 14 to 2 advantage in the third period.

The knowledge they could advance with a win Monday night and not have to return to Dallas did not prevent a poor start to the game for the Blues.

Dallas scored on two of their first three shots on goal, with Mattias Janmark and Vernon Fiddler, celebrating his 36th birthday, getting the goals just 20 seconds apart in the first 5:13 of the opening period.

Jason Spezza increased the lead to 3-0 with a power-play goal, his first goal of the series, at 16:49 after Troy Brouwer was called for cross-checking. It was only the Stars' second power-play goal in 17 opportunities in the series.

The Blues pulled goalie Brian Elliott after Spezza's goal, which came on Dallas' seventh shot on goal, and inserted Jake Allen for the first time in the playoffs. He last played April 3, logging one period at Colorado.

Elliott had allowed only 10 goals on 158 shots on goal by the Stars in the first five games of the series.

Trailing after the first period for the first time this postseason, the Blues out-shot the Stars 14-5 in the second period but could only score once, on a goal by Alexander Steen off a rebound at 7:29, to cut the Dallas lead to 3-1.

NOTES: RW Patrick Eaves, who had not played since taking a shot off his lower leg in game 1, returned to the Stars' lineup, taking the place of LW Travis Moen, who is dealing with an undisclosed injury. ... The Stars also inserted LW Colton Sceviour, a healthy scratch the last two games, into their lineup in place of LW Brett Ritchie. ... The Blues made one change to their lineup, with D Robert Bortuzzo taking the place of rookie D Joel Edmundson, who made a key turnover which led to a goal in Dallas' win in game 4. Bortuzzo had been a healthy scratch since Game 6 of the first-round series against Chicago. ... RW Dmitrij Jaskin, who scored his first career playoff goal in Game 5, remained in the Blues' lineup in place of RW Ryan Reaves.