Florida Panthers Derek Mackenzie pumps his fist after scoring a goal past St. Louis Blues goaltender Jake Allen in the second period at the Scottrade Center in St. Louis on December 1, 2015. Florida defeated St. Louis 4-1. Photo by Bill Greenblatt/UPI

Florida Panthers Derek Mackenzie pumps his fist after scoring a goal past St. Louis Blues goaltender Jake Allen in the second period at the Scottrade Center in St. Louis on December 1, 2015. Florida defeated St. Louis 4-1. Photo by Bill Greenblatt/UPI

The Florida Panthers got two unassisted goals from Derek MacKenzie as they stopped the St. Louis Blues 3-1 at Scottrade Center on Tuesday.  MacKenzie’s first goal came 13 seconds after Florida’s Brandon Pirri opened the scoring at 12:18 of the second period. He scored again late in the period.  Roberto Luongo made 29 saves, including 17 in the third period, for his 16th career win against St. Louis.

David Backes scored for the Blues (15-7-3), who lost in regulation for the first time in six games. Allen made 12 saves before Brian Elliott replaced him for the third period.  Elliott made eight saves.

“All their offense started from us turning the puck over either in the neutral zone or in the offensive zone,” Blues coach Ken Hitchcock said after his team turned the puck over ten times. “That’s where all their fast breaks started. … Everything’s work-based, and when you play with a work base, you play in straight lines, you don’t play cute, you get on the grind, you wear teams down. That’s how we’re built; we didn’t want to play that way today.”