SASKATOON - Ty Rattie scored the winner in the third period and Mac Carruth made 34 saves as the Portland Winterhawks defeated the London Knights 2-1 in the semifinal of the MasterCard Memorial Cup.

Tyler Wotherspoon also scored for the Winterhawks, who will take on the Halifax Mooseheads in Sunday's final that will determine the Canadian Hockey League champion. Nicolas Petan added two assists.

Max Domi had the goal for the Knights, while Jake Patterson made 32 stops for London, which defeated the host Saskatoon Blades 6-1 in Thursday's tiebreaker game.

Portland's victory now sets up a dream final involving Winterhawks defenceman Seth Jones, the No. 1 ranked North American skater ahead of next month's NHL draft, and Mooseheads forwards Nathan MacKinnon and Jonathan Drouin, who are second and third on the list. Halifax beat Portland 7-4 during round robin play.

Rattie broke a 1-1 tie at 8:32 of the third period, circling in the London zone before rifling his tournament-leading fifth goal upstairs on Patterson from the slot.

The Knights, who were involved in a gruelling Ontario Hockey League final just to get to Saskatoon, seemed to run out of gas as the period continued but still had chances to knot the score.