Trout crushed a 2-2 pitch from Royals starter Jakob Junis over the left field wall in his first at-bat Saturday night. The ball traveled a projected 473 feet, according to Statcast.
Trout's home run was his longest since a 477-foot shot on July 8, 2015, against the Colorado Rockies at Coors Field.
Trout is hitting .297 with 10 home runs and 27 RBIs this season. He leads the American League with a .468 on-base percentage and has walked 41 times in 186 plate appearances.
The Angels are 22-23 this season. Los Angeles trails the Houston Astros by 8 1/2 games in the AL West Division.