Lavell Ika scored the go-ahead touchdown with 1:35 remaining, and Southern Utah's defense stopped Portland State at the 1-yard line on the final play to hold on for a 49-42 victory on Saturday night.
Brad Sorensen threw for 311 yards and four touchdowns as the Thunderbirds (2-2, 1-0) won their first-ever Big Sky conference game. They outscored the Vikings 14-0 in the fourth quarter and never led before Ika's TD, a 1-yard rush.
Portland State (1-3, 1-1) furiously drove 66 yards in to face first and goal at the 2, but Kiernan McDonagh threw two incompletions before being stopped on a quarterback sneak.
McDonagh threw for 270 yards and a touchdown. The Vikings had 317 rushing yards.
Mitch Jessop caught nine passes for 159 yards and two touchdowns for the Thunderbirds. His 39-yard TD reception in the fourth quarter tied the game at 42-42.