Bronson Arroyo threw a six-inning complete game and Todd Frazier belted a three-run homer and drove in four runs, as the Cincinnati Reds pounded the San Francisco Giants, 8-1, on a rainy night at Great American Ball Park.
Derrick Robinson had a two-run double and Zack Cozart also knocked in a pair as the Reds won for just the third time in their last 10 games.
Arroyo (7-6) allowed two hits and had three strikeouts to log his first complete game of the season and 14th of his career. He also broke a personal four-game winless skid and moved to 6-1 at home this year.
Mike Kickham (0-3) struggled in his third major league start. The lefty surrendered nine hits and seven runs over 2 2/3 innings to watch his ERA climb to 13.94.
Brandon Belt homered for the Giants, who have lost seven of their last eight contests.
The Reds scored four times in the second and three more in the third to take control in the opener of this four-game series.
Brandon Phillips singled to center and Jay Bruce followed with a double to left-center to start the bottom of the second. Frazier then grounded a base hit through the left side for the first run. Cozart's line drive to left field plated Bruce.
Ryan Hanigan then legged out an infield hit, and following Arroyo's sacrifice bunt, Robinson bounced a ball over the head of third baseman Pablo Sandoval to account for a 4-0 margin.
"It was beautiful," Arroyo said of the run support. "It allows you to pitch free and easy."
Singles from Joey Votto and Bruce in the third led to Frazier's one-out, three-run blast to left-center.
Belt homered to right leading off the fifth.
Zack Cozart added an RBI double in the fifth, and thunderstorms erupted, causing the tarp to be placed on the field entering the seventh inning.
The game was called following a 1-hour, 28-minute delay. The field was inundated with water, especially down the first and third-base lines.
"You want to play, but with what you're looking at, it's coming down harder, you've got a flood in there. At some point, you have to draw the line," Giants manager Bruce Bochy said.
Arroyo is the first Reds pitcher to throw a rain-shortened complete game since Cory Lidle, April 22, 2004 against Atlanta, a five-inning game ... The Giants are 14-19 all-time at Great American Ball Park, losing eight of their last nine games ... The Giants are just 2-for-22 with runners in scoring position in their last five games