CINCINNATI -- The Colorado Rockies arrived at Great American Ball Park on Wednesday afternoon prepared to face Cincinnati's No. 1 starter, Johnny Cueto. As it turned out, Cueto was placed on the disabled list with a strained right shoulder, and Triple-A righty Pedro Villarreal was summoned to make his first major league start.
"When you know you're going to face a guy like Johnny Cueto, one of the best pitchers in the game, you come to the ballpark with a certain mindset," said Rockies left fielder Carlos Gonzalez. "First thing you know, they bring in a guy you've never faced before. It's a weird feeling. But we saw a lot of good pitches around the strike zone."
The Rockies hit six homers, including three by Gonzalez and two by shortstop Troy Tulowitzki, highlighting a 20-hit outburst in a 12-4 victory.
Colorado (32-28) took two of three games in the series, only the second losing series at home for Cincinnati this season.
"It's a tough place to come in and win a series," said Rockies manager Walt Weiss. "It's a boost of confidence for us to win a series on the road against a club like that."
One of Gonzalez's homers, a three-run shot in the fourth, traveled an estimated 476 feet into the right-center field seats.
"It's tough for a human not to watch a ball hit that far," Gonzalez said.
Todd Helton added a solo home run in the seventh, extending his hitting streak to six games.
"I've found a little something," Helton said. "I hope to keep building on it and keep getting good swings."
Tulowitzki and Gonzalez hit back-to-back homers in the eighth. Tulowitzki tied a career-high with five hits. Gonzalez went 3-for-5 with six RBIs and homered three times for the second time in his career.
Third baseman Nolan Arenado had a career-high four hits.
Lost amid the offensive barrage was an impressive outing by Rockies right-hander Jon Garland. After a rocky first inning, Garland (4-6) was dominant, retiring 16 of the final 17 batters to earn the victory.
"Great job by Jon to fill up those zeroes after the first inning," Weiss said. "He's been grinding his past four or five outings."
Reds left-fielder Xavier Paul hit a three-run home run off Garland in the first to put Cincinnati ahead 4-1. But Jack Hannahan, who doubled in the fourth, was the only baserunner Garland allowed over the next five innings.
Colorado came out swinging against Villarreal, who made just his second career appearance in Cueto's place.
"I was just glad to be up here to pitch," Villarreal said. "Obviously, they're a good ballclub and they showed it today."
Villarreal (0-1) allowed six runs on 10 hits in 3 2/3 innings and three home runs.
"The young kid had a rough night," said Reds manager Dusty Baker. "He was leaving balls up in the zone and out over the heart of the plate. You do that and you're in trouble."
Gonzalez's solo home run put the Rockies ahead 1-0 in the first. In the fourth, Gonzalez launched his three-run bomb to right-center, giving Colorado a 6-4 lead.
"He was trying to come in and he left it up," Gonzalez said of the pitch by Villarreal. "Those are the kind of pitches you can't miss at this level."
Following an RBI single by Todd Frazier, Paul launched a 3-2 pitch from Garland into the right-field seats for a three-run homer, giving Cincinnati a brief lead.
The Rockies offense took over from there.
"That was a real whipping," Baker said. "I haven't seen that many balls hit that hard. Once you start, it's contagious, up and down the lineup. We have to put it past us."
NOTES: Cueto was placed on the 15-day disabled list for the second time this season on Wednesday with a strained muscle in his right shoulder, and Villarreal was recalled from Triple-A Louisville. Cueto said he felt soreness in the eighth inning Friday at Pittsburgh and expects to miss just one, or possibly two starts. "It's the same thing he had before," Baker said. "He doesn't have to go back to square one like he did the last time." Cueto was 2-0 with a 1.80 ERA in four starts since coming off the DL on May 20. ... An MRI conducted Tuesday on Rockies RHP Tyler Chatwood showed minor inflammation in his right triceps and he is expected to miss one start. Chatwood left Monday's game after four innings with right triceps soreness. He will sit out his scheduled bullpen sessions on Wednesday and Friday. ... Rockies CF Dexter Fowler did not start Wednesday's game due to illness. ... Gonzalez's fourth-inning homer was the 11th longest in Great American Ball Park history. ... Colorado hit six homers for the sixth time in franchise history and tied a Great American Ball Park record for home runs by an opponent.