CINCINNATI -- Reds right hander Bronson Arroyo allowed just four hits over eight innings, and Jay Bruce went 3-for-4 including a two-run home run, lifting Cincinnati to a 3-0 victory over the Colorado Rockies in the opener of a three-game series Monday night.
Cincinnati (36-22) improved to 21-7 at Great American Ball Park. Colorado (30-28) was shut out for the fourth time this season.
Rockies starting pitcher Tyler Chatwood (3-1) left after four innings due to right triceps soreness.
The Reds were clinging to a 1-0 lead with two outs in the eighth when Bruce launched a 1-1 pitch from Josh Outman an estimated 454 feet into the right field seats to extend the margin to 3-0.
Aroldis Chapman struck out three in the ninth to earn his 15th save.
Arroyo (6-5) was on cruise control for most of the night. He struck out three and didn't walk a batter over 86 pitches.
Arroyo retired 15 of 16 batters in one stretch, including 10 straight after giving up a leadoff single by Carlos Gonzalez in the fourth. Arroyo needed just 65 pitches to get through six innings.
With two outs in the fourth, Bruce singled on an 0-2 pitch, stole second and scored on Todd Frazier's single to put Cincinnati ahead 1-0.
It was Bruce's first stolen base this season and the first run allowed by Chatwood in three road starts.
Chatwood grounded out catcher-to-first to end the fifth and pulled up while running to first. He was replaced by Rob Scahill after giving up one run on five hits with four strikeouts over 64 pitches.
A bizarre play occurred with one out in the seventh and Colorado's Michael Cuddyer on first. Todd Helton swung at a pitch that hit the ground, and he lined out to Reds third baseman Frazier, who threw to first for an apparent double play. However, the umpires ruled it a 5-3 putout. Frazier and Reds manager Dusty Baker argued the call to no avail. Cuddyer reached second on the play, but Wilin Rosario flied out to right to end the inning.
NOTES: Reds 2B Brandon Phillips missed his second straight game with a bruised left forearm after being hit by a Tony Watson pitch during Saturday's win at Pittsburgh. X-rays were negative, but Phillips might not return until Friday when the Reds open a three-game series at home against the first-place St. Louis Cardinals. Cesar Izturis made his fourth start at second base, 11th overall. He went 0-for-4. ... Rockies 3B Nolan Arenado batted second, but manager Walt Weiss said the No. 2 spot will remain fluid. Arenado finished 0-for-4. ... Plate umpire Kerwin Danley left the game after being struck by a foul ball in the second inning. Lance Barksdale took over behind the plate in the third. ... Cincinnati went 5-1 last season against Colorado, including a 2-1 mark at Great American Ball Park.