DENVER (AP) — For two games, Jarrod Parker sat around and waited for his turn to take the mound, watching two pitching staffs get roughed up to the tune of 31 runs.

And then the unflappable kid did what few pitchers can do, he tamed Coors Field.

Parker allowed three hits over seven scoreless innings, and Brandon Moss drove in three runs to help the Oakland Athletics beat the slumping Colorado Rockies 8-2 on Thursday for their first series sweep on the road since the end of the 2010 season.

Parker (3-3) was bumped up a spot in the rotation due to Brandon McCarthy’s sore shoulder, so he drew the assignment of throwing in this hitter friendly park.

The hard-throwing righty allowed just three singles before being lifted after tossing an efficient 89 pitches. Parker struck out six and walked one.

“He’s got some grit and determination to him,” A’s manager Bob Melvin said. “It’s difficult to sit here and watch balls fly all around this park like it’s a pinball machine and then go out there and throw seven innings with three hits and no runs.”

Not for a poised Parker. He made it look rather easy with a simple philosophy — don’t leave anything up.

“You can’t get hurt on the ground,” Parker said.

Or if hitters struggle to catch up with a lively 94-mph fastball.

Just when they think they’ve figured him out, Parker mixes in an 83-mph changeup.

“When he’s pitching well, everybody is in between. Just a little bit behind the fastball and ahead of the changeup,” Melvin said.

Parker was in control the entire way, allowing just one runner to reach third base. Even then, he quickly quieted the threat by striking out Carlos Gonzalez on a changeup to end the sixth.

The 23-year-old Parker was recalled from Triple-A Sacramento on April 25 and has been a solid contributor in the rotation.

With this performance, he lowered his ERA from 3.19 to 2.82. That is usually not the case at Coors, where ERAs tend to go up.

“Their young kid was terrific,” Rockies manager Jim Tracy said. “We could do very little with him.”

Or with Moss at the plate.

The first baseman has been swinging a hot bat since being brought up from Sacramento on June 6. Moss hit his fifth homer in eight games, a solo shot to right-center in the ninth. He also had a two-run double in the third.

“He’s been a nice acquisition for us,” Melvin said.

Josh Reddick added a solo shot into the second deck in right field for his 15th homer of the season.

The Rockies played shoddy defense as they dropped their season-high eighth straight. They committed three errors, and catcher Wilin Rosario had two passed balls.

Alex White (2-5) surrendered four runs — two earned — in four innings before giving way to Guillermo Moscoso, who pitched three effective innings.

By then, the damage was done and the A’s put the finishing touches on a three-game sweep.

The Rockies remain the only team in the majors this season without an interleague win. They are 0-9, but still remain one of the NL’s top interleague teams since 2006. The Rockies are 56-46 against the American League during that time.

“We’ve got to do something different,” said White, who was dealing with a blister on his middle finger after the game. “We’ve got to find a way to win a game here and there, get on a streak because this is tough to watch, tough to be a part of, and we’re all sick of it.”

Oakland jumped out to a 2-0 lead in the second when third baseman Jordan Pacheco misfired to first on Adam Rosales’ slow roller. The throw was in the dirt, and Tyler Colvin, who was filling in for the sure-handed Todd Helton, couldn’t scoop out the throw as Moss easily scored, along with a hustling Kurt Suzuki.

The Rockies got on the scoreboard in the ninth when Marco Scutaro lined a solo homer to left off former Colorado closer Brian Fuentes. Colvin soon followed with an RBI double before Fuentes ended the game by striking out Rosario.

The A’s were missing slugger Yoenis Cespedes a day after he left because of a strained left hamstring.

Melvin said Cespedes will do some running drills to test out the hamstring when the team returns to Oakland. He could possibly serve as the designated hitter for a weekend series against San Diego.

Cespedes originally injured the hamstring last Thursday while running out a grounder against Texas. The Cuban rookie tweaked it again running out a grounder in the first inning on Wednesday.

NOTES: McCarthy was scheduled to played catch Thursday, but Melvin said he is doubtful for a start on Saturday. ... There was a haze off in the distance from a massive northern Colorado wildfire. ... The Rockies might be without All-Star SS Troy Tulowitzki a little longer. Tulowitzki aggravated a groin injury in a rehab assignment and will undergo a precautionary MRI. He is eligible to come off the DL on Friday in Detroit, but Tracy wasn’t sure if Tulowitzki would make the trip.