CINCINNATI — Bronson Arroyo's pitches were moving so unpredictably to the first few batters that catcher Ryan Hanigan went out to the mound with a funny suggestion.

"He said, 'You're so bad today, I'm going to set (the mitt) down the middle and you throw it,"' Arroyo said.

No need to get so drastic.

The right-hander quickly got things under control and pitched into the eighth inning for his fifth straight win, leading the Cincinnati Reds to a 4-0 victory over the Pittsburgh Pirates Wednesday night.

Arroyo (5-2) allowed five hits — all singles — in 7X\c innings. He walked Aki Iwamura to start the game, then managed to get his pitches going where he intended.

"Sometimes you feel funky out there," said Arroyo, who also had trouble with his control warming up. "I couldn't get a groove going. I got out of that (first inning) and my command came back. I kind of got on a roll."

He started fading in the eighth on a warm, muggy night, leaving after his 113th pitch. Daniel Ray Herrera pitched out of a bases-loaded threat, striking out Garrett Jones on a 66 mph screwball to end Pittsburgh's last chance.

Orlando Cabrera drove in two runs, and Miguel Cairo had a solo homer off Ross Ohlendorf (0-3), who was in trouble most of his six innings. The right-hander gave up eight hits and walked five, also struggling at the outset.

Ohlendorf missed roughly a month because of back spasms. He's 0-3 since his return from the disabled list and still trying to get back in form. He walked three in the first two innings, setting himself up for a tough time.

"I'm definitely not pitching like I'd like to," Ohlendorf said. "After the first two innings, I felt a lot better. I was able to relax and trust my stuff more. I was nibbling in the first two innings."

Manager John Russell liked the way Ohlendorf pitched after those ragged, opening innings.

"I think it's a step in the right direction," Russell said. "Once he picked up the tempo, he threw the ball pretty well. I hope he builds off it and has confidence when he takes the mound."

The Reds have won eight of 12, jostling with the St. Louis Cardinals for the top spot in the NL Central. They began the day with identical records.

Pittsburgh has been shut out seven times, most in the NL. Things don't get any easier for the Pirates today in the finale of the four-game series — they face Johnny Cueto, who threw a one-hitter for a 9-0 win in Pittsburgh May 11.

The Pirates have scored the second-fewest runs in the NL. They got only one runner to third base against Arroyo, who tends to be streaky. He's on quite a tear now. The right-hander is 5-0 in his last six starts, allowing only 13 earned runs.

Second baseman Brandon Phillips made two impressive plays behind Arroyo, ranging far to snag a grounder and to start a difficult double play in the sixth, then leaping well off the ground to snag Lastings Milledge's liner in the seventh.

Notes: Pirates 3B Andy LaRoche missed his fifth straight game with a sore back.