DENVER -- In his pre-game bullpen session, Jhoulys Chacin had trouble getting the ball over the plate. He had no problem when the pitches really counted.

Chacin pitched seven strong innings in his third start since returning from the disabled list, Dexter Fowler hit his first career grand slam, and the Colorado Rockies beat the San Diego Padres 9-1 on Saturday night.

Tyler Colvin also homered and doubled to drive in three runs to help the Rockies cool off the Padres, who had won 10 of their previous 11.

"It really wasn't a good bullpen," Chacin said "I was throwing too many balls. Then, I got to the game and I just let the ball go, doing what I've been doing and having fun. My arm just feels good. My body feels good. I'm throwing the ball for strikes and getting quick outs."

Chacin (2-4) allowed one run on five hits for his second win this season, both of them coming since his Aug. 21 return after more than three months on the DL because of inflammation in his pitching (right) shoulder. He struck out four and walked two.

It was the first time a Rockies starting pitcher had gone seven innings since the team instituted its unorthodox four-man rotation with a roughly 75-pitch limit per outing June 19 (Chacin had 74 pitches). The last starter to go that long in a game was Christian Friedrich on June 4 against Arizona.

"He was unbelievable," Fowler said of Chacin. "That's the best I've seen him, so it's a bright side, especially coming off the injury."

Said Chacin: "When you've got 75 pitches, the only thing you can do is try to throw strikes and get quick outs. I was able to do that today and that's why I was able to go seven innings."

Edinson Volquez (9-10) went 4 2/3 innings and allowed five runs on nine hits in losing to the Rockies for the first time in three starts this season. He struck out five and walked three.

Volquez said he put his pitches where he wanted them for the most part.

"It was good. Down in the zone," Volquez said when asked about his pitching command. He said the Rockies had a "lot of bloopers. That happens sometimes. You can't complain. It's part of the game."

The Rockies went in front in the first inning when Carlos Gonzalez doubled and scored on Wilin Rosario's single.

Colvin made it 2-0 when he led off the second with his 16th homer of the season, driving the first offering from Volquez over the center field wall.

The Rockies added three more runs in the fifth. Josh Rutledge singled -- one of his three hits on the night -- and Rosario walked before Colvin lined a double to left to score both of them. After Jordan Pacheco walked, Chris Nelson lined an RBI single to left, chasing Volquez.

The Padres got on the board when Will Venable led off the sixth with a home run, his ninth of the season.

But the Rockies more than offset that in their half of the eighth, loading the bases with help from a fielding error by shortstop Alexi Amarista and a bloop pinch-hit single by Jason Giambi. Fowler followed with a drive off reliever Miles Mikolas that cleared the center field wall for his 13th homer of the season.

"It felt awesome, especially sitting there 0 for 4 with two strikeouts and not feeling like I had contributed at all. So it was good to get a hit there," Fowler said.

Game notes

Pitchers Andrew Cashner and Joe Thatcher have been reinstated from the 15-day disabled list by the Padres. Thatcher, a left-hander, is expected to work out of the bullpen while Cashner could see duty both as a reliever and starter in the final month of the season. ... LHP Jeff Francis (5-4) pitches Sunday's series finale against the Padres' RHP Casey Kelly (1-0). ... In addition to activating first baseman Jason Giambi from the 15-day disabled list following his recovery from a viral infection, the Rockies recalled right-handed pitcher Guillermo Moscoso from their Triple-A affiliate in Colorado Springs. ... Jordan Pacheco extended his hitting streak to 10 games with a one-out double in the fourh inning.