DENVER -- The Colorado Rockies' approach against the San Francisco Giants on Tuesday night was not the norm. The result was.

Using their relief corps the entire game, the Rockies continued their season-long dominance of the Giants at Coors Field with a 9-6 victory.

It was the fourth time in franchise history that Colorado used nine or more pitchers in a nine-inning game -- which is one shy of the club record -- and the first time since Sept. 23, 2015.

The win enabled the Rockies to increase their lead over Milwaukee to 2 1/2 games for the second National League wild-card spot. The Brewers dropped their second-straight game at Cincinnati, falling 9-3 to the Reds.

The Rockies will try to sweep the series Wednesday and win three straight for the first time since Aug. 3-5.

The Giants, who have lost seven of their past eight games and 10 of their past 12, fell to 0-9 at Coors Field this season and have lost 10 straight games there dating back to last season. The last time the Giants lost 10 consecutive road games to one opponent was when they dropped 11 in a row to the Cincinnati Reds from Sept. 11, 1984-Sept. 17, 1985.

The Giants staged a comeback, scoring two runs in the seventh and three in the eighth to whittle the Rockies' lead to one run. But with the tying run at first base and two outs in the eighth, Adam Ottavino came on to face Buster Posey. Ottavino fell behind 3-0 but struck Posey out on seven pitches, the last a cutter that Posey waved at as it broke well off the plate.

After throwing five straight fastballs, Ottavino threw an 81 mph slider. Catcher Jonathan Lucroy said he called for another slider because, "It's Buster Posey, you can't give him a fastball right there."

Much to Lucroy's surprise, Ottavino threw an 89 mph cutter.

"I went rogue a little bit there," Ottavino said. "It wasn't supposed to be that far outside."

Posey left the game in the eighth after being hit with a foul tip.

"He had a contusion on the fourth finger on his right hand," Giants manager Bruce Bochy said. "It swelled up pretty good right when it happened, so that is good news that the X-rays were negative."

Doubles by pinch hitter Carlos Gonzalez and DJ LeMahieu in the eighth made it 9-6.

With no one holding down the No. 5 starter's spot, the Rockies by design went to a bullpen game when that turn came up Tuesday. Colorado shuttled nine pitchers to the mound. The last was Greg Holland, who earned his first save since Aug. 24 and his 37th in 41 chances.

Tyler Chatwood who began the season in Colorado's Opening Day rotation but was since demoted, made his first start since Aug. 2. He held the Giants scoreless for three innings but needed 61 pitches and threw just 28 strikes.

Chatwood gave up four hits and walked three with three strikeouts. He got five outs on ground balls as the Rockies turned double plays in the first and second. Chatwood struck out Hunter Pence to end the third with the bases loaded after giving up a walk and two singles in the inning.

"We turned him loose for 60 pitches," Rockies manager Bud Black said, "with the expectation for him to go as hard as he can for as long as he can. And that's what he did."

Chris Rusin (4-0), who followed Chatwood to the mound and gave up one run in 1 2/3 innings, was the winning pitcher.

The Rockies' four-run sixth gave them a 6-1 lead. The rally included run-scoring doubles by Nolan Arenado, Mark Reynolds and Ian Desmond and Lucroy's run-scoring single. Arenado, who led the majors in RBIs each of the past two years, has 112, tying him with Miami's Giancarlo Stanton for the major league lead.

Posey doubled home two runs with one out in the seventh to make it 6-3. Zac Rosscup then got Brandon Crawford to fly out, and Pat Neshek retired Hunter Pence to end the inning.

The Rockies tacked on a run in their half of the seventh on Gerardo Parra's infield single as his grounder went off the glove of diving first baseman Ryder Jones.

With two outs in the eighth, the Giants scored three runs before Ottavino's confrontation with Posey.

Giants starter Ty Blach (8-12), who was born and raised in Denver, gave up five hits and five runs in 5 1/3 innings and fell to 0-5 with a 7.90 ERA in his past five starts. His outing came one year to the day after he made his major league debut at Coors Field.

"It's been a good learning experience," Blach said. "Obviously, there has been a lot of ups and downs. I'm just trying to focus on the positives and just trying to enjoy every minute and get better every day. Every day here is a blessing, and (I'm) just trying to make the most of it and take advantage of the opportunity."

NOTES: Giants 3B Pablo Sandoval, who went 0-for-4 with a walk, is hitless in his past 37 at-bats. ... Rockies 2B DJ LeMahieu extended his season-high hitting streak to 13 games. ... RHP Shane Carle was recalled from Triple-A Albuquerque to begin his third stint with Colorado this season. ... Giants RHP Roberto Gomez had his contract selected from Triple-A Sacramento and made his major league debut, as did RHP Reyes Moronta, who was recalled from that team. To make room on the 40-man roster for Gomez, OF Carlos Moncrief was designated for assignment. OF Austin Slater (right groin strain) was reinstated from the 10-day disabled list. ... Rockies INF/OF Ian Desmond and Giants C Buster Posey were nominated by their teams for the 2017 Roberto Clemente Award.