Erik Karlsson scored the winner in the sixth round of the shootout as the Ottawa Senators defeated the Calgary Flames 5-4 after blowing a big lead in regulation Sunday night.

Alex Chiasson, Milan Michalek, Mark Borowiecki and Mike Hoffman scored for the Senators, who led 4-0 in the third period before giving up four straight goals to allow the Flames to tie it. Craig Anderson made 42 saves.

Kris Russell scored twice for the Flames, while Joe Colborne and Mikael Backlund had one each.