The top pick of the 2015 Draft drove in a run in the fifth inning, scored the tying run in the bottom of the ninth and delivered a walk-off single in the 13th to give Hillsboro the 6-5 win over Salem-Keizer.
"The biggest thing was just to relax," Swanson told MiLB.com. "Sometimes in those situations, you try to do too much and press. I tried to stay in the middle of the field. I give a lot of credit to the guys before me for getting on."
Swanson, who twice helped Vanderbilt reach the championship round of the College World Series, has hit .289 with seven doubles, three triples, a home run and 11 RBIs in 22 games. He is ranked the No. 10 prospect in baseball by MLB.com.
The 21-year-old led off the bottom of the ninth with a walk, reached third on a double and scored on a base hit. Salem-Keizer had two errors in the 13th that loaded the bases for Swanson, whose game winner off Nathaniel Santiago went over the center fielder's head and nearly reached the warning track.
Hillsboro hosts Tri-City in Game 1 of the best-of-three Championship Series on Thursday.
Joey Nowak is a reporter for MLB.com. Follow him on Twitter at @joeynowak. This story was not subject to the approval of Major League Baseball or its clubs.