Torgersson, a second-round pick (No. 40) by the Jets at the 2020 NHL Draft, gave them a 1-0 lead at 13:55 of the first period, then put them in front 3-2 at 15:11 of the second period.
Kyle Connor had a goal and two assists, and Connor Hellebuyck made 23 saves for Winnipeg.
Tyler Motte and Shane Pinto each had goal and an assist for Ottawa. Mads Sogaard made eight saves in 29:48, and Kevin Mandolese allowed four goals on 15 shots in relief.
Cole Reinhardt tied it 1-1 for the Senators at 14:35 of the first, and Motte gave them a 2-1 lead at 7:40 of the second.
Michael Eyssimont scored on the power play for the Jets at 13:44 of the second to tie it 2-2 before Torgersson's second goal of the game less than two minutes later.
Ville Heinola's power-play goal at 19:10 of the second gave Winnipeg a 4-2 lead, but Pinto scored 26 seconds later to cut it to 4-3 at 19:36.
Connor scored at 8:10 of the third period for the 5-3 final.
