The 22-year-old Cuban defector allowed three hits and no runs in his 5 2/3 innings, striking out seven and walking three. He threw 96 pitches, 63 of them strikes.
Chapman (4-2) got credit for the 4-2 victory while lowering his ERA to 3.98 in eight Triple-A starts. He has 48 strikeouts and 24 walks in 40 2/3 innings.
In his previous start at Rochester, Chapman allowed eight earned runs and nine hits over 3 1/3 innings. He was pulled during a six-run fourth in which he allowed a three-run homer. Rochester won that game, 13-4.