Clayton Richard struggled at Coors Field. He's pretty sure he would have been bad in any ballpark though.

In 5 1-3 innings, the Padres starter yielded eight runs on 10 hits, including six doubles and two homers, and the Colorado Rockies beat San Diego 8-4 Wednesday night.

"If I was pitching in San Diego," Richard said, "it would have been a bad night the way I was throwing."

Richard (1-1) gave up five runs in the second on five hits, all for extra-bases. The onslaught included a two-run double by Wilin Rosario, a two-run homer by Jonathan Herrera, a run-scoring double by Dexter Fowler. Michael Cuddyer hit a two-run homer in the fifth, and pitcher Juan Nicasio singled home a run in the sixth for his first RBI in the majors.

Richard came close to tying his career high of 11 hits. That dubious record was also set at Coors Field, on Sept. 15, 2010.

"In the second inning, he got the fastball up out over the plate," Padres manager Bud Black said. "When you get the ball up out over the plate in this park and the Rockies are able to put good wood on it and get it up in the air, you saw the results. When a pitcher like Clayton gets the ball up, his ball flattens out. When he gets it down, the ball sinks. Tonight was a classic case of that."

Chase Headley had his first career multihomer game, hitting a solo shot in the first and a two-run one in the sixth, both to the opposite field and off Nicasio (1-0).

The Rockies' starter won in his second start at Coors he was struck in the right temple with a line drive Aug. 5, fracturing his skull and a vertebra.

Headley has hit four homers in 46 at-bats in 13 games, as many homers as he hit in 113 games and 381 at-bats last season.

"I'm not going up there trying to hit home runs, but I do think there's a lot more power in there that really hadn't been shown the last couple years," Headley said. "So I wanted to get my swing to where at least when I hit the ball when I'm capable of it's going to have a chance go out of the ballpark."

Headley's first homer was on a 97 mph fastball in an 0-2 count with two out and the bases empty, and the second came on a 2-1 changeup two out and a runner on third.

"My first at-bat, he goes changeup on the first pitch, painting on the black away," Headley said. "And then a fastball painting on the black away. I step out of the box and was like, 'What're you going to do with those?' He pitched tough. He pitched down in the zone for the most part. He made a couple mistakes, but I thought he threw the ball really well."

Richard got seven groundball outs through four innings, including three in the third and two in the fourth after the Rockies roughed him up in the second. But he gave up his first single in the fifth and his second and last one in the sixth, the grounder up the middle by Nicasio that finished Richard.

"When we sent him back out there in the sixth, he had (a pitch count in the) mid-70s," Black said. "We were hoping he could get us through seven innings and really clean up our bullpen."

Richard is 0-3 with a 9.00 ERA in five starts at Coors Field. The San Diego Padres return to Coors Field in late June and late August.

NOTES: Rockies right fielder Michael Cuddyer was removed after the sixth with a bruised left big toe. ... Black said it was a good time to rest OF Cameron Maybin, who is 2-for-19 on the road trip and hitting .170 overall. Maybin has been leading off for the Padres, but Black said, "Don't be surprised if he hits somewhere different tomorrow." ... Todd Helton's double in the third was No. 558 in his career, putting him two away from of tying Hall of Famer Eddie Murray and Jeff Kent for 22nd on the career list. ... The Rockies are off Thursday, and Jhoulys Chacin will start at Milwaukee on Friday. Joe Wieland will start Thursday for the Padres against the Phillies. ... Padres pitcher Tim Stauffer (strained right elbow) threw a bullpen session in San Diego and will throw another one Friday or Saturday. Padres OF Carlos Quentin, recovering from surgery on his right knee, hit on the field in San Diego and did some light running. Padres INF Logan Forsythe (fractured left foot) is about seven to 10 days away from joining Triple-A Tucson. He's hitting off a tee and running in extended spring training.