DENVER — Cincinnati Reds starter Bronson Arroyo managed to minimize the damage in the first inning, always a good sign considering his dismal history in Coors Field.
However, he gave up a three-run homer to Todd Helton in the fourth, part of a barrage of six straight hits Arroyo allowed at the outset of Colorado's five-run inning that he didn't finish.
The Rockies beat the Reds 9-6 as Helton homered twice and matched a career high with six RBIs.
"I was rolling along. I felt as good as I've ever felt in this ballpark," Arroyo said. "It's a bit difficult for me, given I'm a guy who uses his breaking ball a lot, which is tough to throw here. That's about as good as I can feel. Felt good, I felt strong. Felt it was a really manageable lineup."
The onslaught in the fourth began with an infield single by Troy Tulowitzki, who hit a chopper to shortstop. Wilin Rosario singled, and Helton drove a 1-0 changeup into the Rockies' bullpen in right-center to put the Rockies ahead 4-2.
After two more singles, Charlie Culberson drove in two runs with a double. Arroyo (13-10) got pitcher Jorge De La Rosa to ground out and then was lifted from the game. In six starts at Coors Field, Arroyo is 1-3 with a 7.94 ERA.
"`Tulo' started that inning of with a funky chop hit, and I couldn't put the lid on that can of worms he opened," Arroyo said. "That's just the way it rolls sometimes."
Arroyo gave up nine hits over 3 1-3 innings in his shortest start of the season. Arroyo gave up a one-out walk in the first, ending a 30-inning string without one and had his four-game winning streak snapped.
He pitched 3 2-3 innings against St. Louis on Aug. 2, but came into this game 4-0 with a 2.33 ERA in his past four starts.
"That's kind of Bronson," Reds manager Dusty Baker said. "When it happens, it happens quickly. Bronson being a contact kind of fly ball pitcher, this ballpark is not conducive to his style of pitching."
Helton homered again in the seventh off reliever Logan Ondrusek, his 11th of the season. Both times, Tulowitzki and Rosario hit successive singles to set the table for Helton, who also had six RBIs against the Los Angeles Dodgers on May 29, 2003.
Tulowitzki singled and Rosario doubled to put runners at second and third in the eighth when Helton, given a rousing ovation by the crowd, came up for his final at-bat. But newly recalled reliever Zach Duke struck him out on seven pitches. The crowd stayed on its feet during the entire at-bat and cheered Helton as he walked back to the dugout.
De La Rosa (15-6) allowed three runs and eight hits to win his fifth consecutive start. He improved to 9-1 with a 2.73 ERA in 13 home starts this season.
The Rockies also touched up Arroyo for a run in the first when rookie Corey Dickerson led off with a triple and scored on D.J. LeMahieu's double.
The Reds tied it in the second on the first of Ryan Hanigan's two RBI singles. He also singled home Todd Frazier, aboard on a leadoff double, in the fourth.
Ludwick hit a two-out solo homer in the fourth to make it 2-1. In the sixth, with the Rockies in front by three, Ryan Hanigan was hit by a pitch and pinch-hitter Cesar Izturis doubled to put runners at second and third with one out. But De La Rosa got Shin-Soo Choo on a grounder and struck out Brandon Phillips, the last batter he faced.
Phillips hit a two-run single off reliever Jeff Francis in the ninth, and Devin Mesoraco had a sacrifice fly.
NOTES: Before the game, the Reds recalled Duke from Triple-A Louisville to add a left-hander to their bullpen. RHP Nick Christiani was optioned to Louisville to make room. ... Rockies RHP Juan Nicasio (8-6) is set to pitch the second game of the series against Reds RHP Greg Reynolds (0-2).