Iginla found himself on a partial breakaway thanks to a nice pass from Alex Tanguay. St Louis defenseman Wade Redden knocked the puck away, but Iginla stayed with the puck to score a goal.
Roman Cervenka scored twice and Miikka Kiprusoff stopped 36 of 38 shots.
T.J. Oshie had a goal and an assist for the Blues, who had won four of their past five.
JETS 3, LIGHTNING 2
In Winnipeg, Manitoba, Bryan Little had a goal and two assists as Winnipeg made Tampa Bay’s bad day worse.
The Lightning fired coach Guy Boucher earlier in the day, and assistants Martin Raymond and Dan Lacroix shared coaching duties against the Jets.
Defensemen Dustin Byfuglien and Tobias Enstrom also scored for Winnipeg, while Blake Wheeler picked up two assists.
Steven Stamkos scored his league-leading 22nd goal of the season on the power play and rookie Cory Conacher also scored for the Lightning.
Winnipeg goalie Ondrej Pavelec made 23 saves, while Cedric Desjardins stopped 21 shots for the Lightning.