CINCINNATI (AP) — Grady Sizemore hit the first of Cleveland’s three homers off Bronson Arroyo, and the Indians remained perfect against their intrastate rival, beating the Cincinnati Reds 8-2 on Friday night.

Cleveland is 4-0 against Cincinnati, which has struggled mightily against the American League. The defending NL Central champs are 5-11 in interleague play.

Sizemore hit his first homer since June 8 off Arroyo (7-7). Asdrubal Cabrera and Carlos Santana also connected.

Justin Masterson (6-6) went eight innings for his first win since April 26. He allowed four hits, including the first of Brandon Phillips’ two solo homers.

The Indians swept Cincinnati in Cleveland from May 20-22, when they were at the peak of their startlingly strong start. That sweep pushed their AL Central lead to a season-high seven games. It’s been downhill since.

Following their 30-15 start, the Indians dropped 22 of their next 34, a swoon that knocked them out of first place.

The Reds? They have stagnated within a few games of .500 since that sweep in Cleveland, unable to put together a winning streak or measure up against the AL.

Masterson hadn’t won in his last 11 starts, partly a function of Cleveland’s offense. The Indians scored only 22 runs in those 11 games, getting shut out four times.

Runs were no problem this time.

Sizemore’s eighth homer got the Indians going in the second inning. He later added an RBI double off Arroyo, who gave up eight runs in 4 2-3 innings. The right-hander has allowed seven homers in his last two starts and 24 homers overall, most in the NL.

Arroyo seemed to have an advantage going in: Shin-Soo Choo was out of Cleveland’s lineup with a broken left thumb. Choo hit four homers off Arroyo last season — the most by any batter off the same pitcher in the majors.

And, with no designated hitter available, the Indians’ lineup also was missing Travis Hafner.

No matter. The Indians pounced on his misplaced pitches just the same.

Arroyo gave up four homers — tying his career high — in a 10-5 victory in Baltimore on Saturday. The Indians kept the trend going.

Sizemore hit a down-the-middle, two-strike pitch for a solo homer. Cabrera added a two-run shot in the third, and Santana homered two pitches later for a 4-0 lead.

By contrast, Masterson has been adept at keeping the ball down and in the park. Phillips led off the fourth with only the fourth homer allowed by the right-hander this season — the first by a right-handed batter. It ended his streak of 36 1-3 innings without giving up a homer.

Notes: The Reds had their eighth sellout of the season. … Cleveland leads the intrastate series 38-35. … The Indians are 10-6 in interleague play. … Indians closer Chris Perez went on the bereavement list to attend his grandmother’s funeral in Florida. He’s expected back on Sunday. … Cleveland called up RHP Josh Judy from Triple-A Columbus. … RF Travis Buck left with a tight left hamstring after running out his two-run single in the fifth. … Masterson singled in his first at-bat, his second career hit. … It was Phillips’ seventh career multihomer game.