Olson's home run was his 20th home run of the season and he added a walk, two runs and two RBIs. Nunez finished the game 4-for-4 with two home runs, a walk, two runs and three RBIs.
Olson leads the California League in home runs and ranks fifth among all Minor Leaguers. He is hitting .249/.399/.524 in 75 games this season.
For Nunez, Wednesday was his first two-homer game of the season and the second of his career. It came a day after the Venezuelan native was named to the World roster for the All-Star Futures Game, which will be played on July 13 at Target Field.
Nunez is hitting .285/.351/.530 with 14 home runs in 67 games this season. He is tied for fifth in the California League in home runs.
Teddy Cahill is a reporter for MLB.com. Follow him on Twitter at @tedcahill. This story was not subject to the approval of Major League Baseball or its clubs.