Chris Iannetta homered twice and had six RBIs and Ryan Spilborghs drove in four runs as the Colorado Rockies battered previously unbeaten Jaime Garcia for 12 runs en route to a 15-4 victory over the visiting St. Louis Cardinals on Saturday.

Iannetta hit a two-run homer in the fourth to finish Garcia’s dreadful outing and added a two-run shot in the eighth as Colorado won for just the third time in 11 games.

Iannetta went 4-for-5 and Spilborghs went 3-for-4 as Colorado rolled up 18 hits in its top offensive effort of the season in support of Juan Nicasio (1-0), who gave up one unearned run and six hits in seven innings in his major league debut. Nicasio struck out two and walked two.

The Cardinals scored six first-inning runs and hammered Garcia (5-1) at will during his 3 1/3-inning stint. Eleven of the runs off Garcia were earned, ballooning the lefthander’s ERA from 1.93 to 3.41.

Iannetta had a two-run single during Colorado’s six-run first. Carlos Gonzalez, Troy Tulowitzki and Eric Young Jr. all had run-scoring singles and Spilborghs drew a bases-loaded walk as the Rockies sent 11 batters to the plate in the opening inning.

The Rockies added a run in the second inning on a two-out single by Spilborghs and exploded for five runs in the fourth on Spilborghs' two-run double and Iannetta’s booming two-run homer to left.

Young also had three hits for Colorado.

Garcia gave up 11 hits and walked four before departing. Garcia hadn’t allowed more than three earned runs in any of his previous 10 starts this season.