CINCINNATI - Bronson Arroyo allowed three runs in six innings, and Todd Frazier homered, lifting the Cincinnati Reds to a 5-3 victory over the Arizona Diamondbacks on Monday in the opener of a four-game series at Great American Ball Park.
Aaron Hill hit his ninth home run in the fourth inning for Arizona.
Reds second baseman Brandon Phillips went 3-for-4 with a triple and two runs scored.
With the victory, the Reds increased their lead to six games over Arizona for the National League's second wild card spot.
Arroyo (12-9) allowed three runs on seven hits with no walks and six strikeouts in his team-leading 18th quality start.
With the bullpen taxed after this past weekend's grueling series in Pittsburgh, including a 16-inning game on Sunday, the D-backs needed innings out of starter Randall Delgado.
Although he took the loss, Delgado (4-4) battled for six innings, allowing five earned runs on seven hits with three walks and six strikeouts over his career-high 114 pitches.
With the Reds leading 5-1, Arizona loaded the bases against Arroyo with one out in the sixth. Martin Prado's two-run single cut Cincinnati's lead to 5-3. But, Arroyo was able to minimize the damage.
Cincinnati's bullpen took over from there. J.J. Hoover struck out two batters in the eighth to extend his scoreless streak to 26 1/3 innings.
The Diamondbacks had the tying run on base in the ninth against Reds closer Aroldis Chapman. But a double play helped Chapman earn his 31st save.
The Reds took the lead in the second inning. Phillips tripled and scored on Zack Cozart's major-league-leading ninth sacrifice fly, putting Cincinnati ahead 1-0.
Arroyo allowed two singles in the first inning then retired the next nine batters he faced, before Hill tied the score 1-1 in the fourth with a line-drive home run to left.
Cincinnati began to square up Delgado's pitches in the fourth. Four consecutive hits, including an RBI single by Jay Bruce and an RBI double down the left-field line by Ryan Ludwick, put the Reds ahead 3-1. The Reds' fourth run scored on an RBI groundout by Cozart.
Frazier's solo home run on Delgado's first pitch in the fifth inning made the score 5-1.
NOTES: Diamondbacks C Miguel Montero, who's on the disabled list retroactive to July 29 with a lower back strain, was expected to catch 3-5 innings Monday night on a rehab assignment with their Arizona League affiliate. Montero went 1-for-5 with a walk and two runs in his first two rehab games. His rehab is expected to last through Saturady, when he'll be reevaluated. ..D-backs CF Adam Eaton is a graduate of Miami (Ohio) University and native of Springfield, Ohio. .. Reds LHP Sean Marshall, on the DL since May 24 with left shoulder tendinitis, resumed his throwing program on Monday. There is no timetable for his return. .. Arroyo hasn't allowed the first batter to reach base in any of his 25 starts. .. Phillips' triple was his first since April 28 of last season. .. Hill's home run extended his hitting streak to 12 games.