TUCSON, Ariz. -- Jhoulys Chacin isn't quite perfect, just very good.
The 21-year-old Venezuelan had not allowed a run, and only one hit, through 7 1/3 innings this spring until Arizona managed three runs off him in the third inning of the Colorado Rockies' 8-3 victory over the Diamondbacks on Monday.
Todd Helton and Carlos Gonzalez each hit a two-run homer for Colorado. Christian Colonel added a three-run shot.
Evan Frey tripled in two runs for Arizona.
Helton, who missed the last half of last season with a back injury, hit his second home run of the spring -- in his 10th at-bat -- on a 3-1 pitch from Cesar Valdez in the first. Gonzalez's first spring homer came on a 1-1 pitch from Travis Blackley in the fourth.
Chacin went three innings, allowing three runs and four hits in his first start after three relief appearances this spring.
"I was a little bit excited," he said.
Chacin won 18 games with Class A Asheville and Modesto last season, compiling a 2.03 ERA. He is 24-8 with a 2.40 ERA in two minor league seasons.
It's not known whether he will start in Double-A or Triple-A this season.
The one bad pitch he made Monday, he said, was the one Frey tripled down the left-field line.
"I was trying to make my pitch, get a groundball," Chacin said. "It was a bad pitch up and he hit it very good."
Chacin got the best of Arizona's Justin Upton, who like Chacin is 21. He retired Upton twice, striking him out to end the third.
"I loved him," Helton said. "He kept the ball down, threw strikes, working ahead. He didn't get rattled when they got guys on base. He's easy to play behind."
Blackley, back from a stint with the Australian team in the World Baseball Classic, gave up two runs and two hits in three innings. He walked four, struck out two and threw a wild pitch. The left-hander is competing for a spot as a long reliever in the Arizona bullpen.
"A little spotty," manager Bob Melvin said. "His breaking stuff was probably better than his fastball was today. He's got to be able to not walk the leadoff guy and throw more consistent strikes. His game I saw in the WBC was better than this one."
After the game, the Diamondbacks optioned Valdez to Triple-A Reno.
Notes
Rockies RHP Aaron Cook went six innings, throwing 78 pitches, in a minor league camp game. He gave up four runs, three earned, and four hits. He also struck out two. ... In addition to Valdez, the Diamondbacks sent seven players to minor league camp -- INF Rusty Ryal, LHP Daniel Schlereth, SS Pedro Ciriaco, RHP Jose Marte, RHP Kyler Newby, LHP Clay Zavada and LHP Leyson Septimo.
