Rookie Jordan Pacheco hit his first career home run and drove in a pair during a four-run rally in the eighth inning as the Colorado Rockies slugged their way to a 12-7 win over the visiting Cincinnati Reds on Saturday.

Jason Giambi added a two-run homer and Mark Ellis hit a solo blast for the Rockies, who knocked Cincinnati starter Bronson Arroyo out in the second inning.

Arroyo, who leads the majors in home runs allowed, surrendered blasts to Ellis and Giambi in the second before being lifted following Dexter Fowler’s two-run shot in the second. That give Arroyo 40 home runs allowed on the season, matching Eric Milton’s franchise record.

The Reds would bash their way back into the game against Colorado rookie Alex White (3-1), getting a pair of home runs in the third and tying it in the fifth when Chris Heisey, Joey Votto and Jay Bruce went back-to-back-to-back.

Playing in his fourth major league game, Pacheco got into the act in the bottom of the fifth, taking a 3-1 fastball from Matt Maloney (0-2) and sending it out to center.

Pacheco’s two-run single in the eighth capped a four-run rally and put the game away.