Allen, who has started four of five for St. Louis due to the struggles of veterans Brian Elliott and Jaroslav Halak, stopped all 28 shots to win his fourth straight. He is 7-1 since being recalled from the minors last month.
St. Louis have back-to-back wins in regulation for the first time since Jan. 24-25. The Blues have won four of five overall.
Alexander Steen celebrated his return to the lineup for St. Louis with a goal and two assists. Steen, who had missed eight games with a shoulder injury, scored his first goal since Feb. 15.
It was definitely emotional. I really appreciated the fans. It was a cool feeling and it felt special and the ovation there at the start and then you kind of feel funny out there standing by yourself. Thinking back, I was saying just a bit ago, you think back just trying to make the NHL and then you kind of reflect on all the years being able to play for a great organization here in Calgary and all the fun I've had so far in my career. I feel very fortunate and blessed.
— Boston forward Jarome Iginla on his return to Calgary, where he played for 16 seasons