Chacon gave up a double to Rafael Palmeiro but nothing else while striking out four. He was followed by Elio Serrano, who fanned three in two hitless innings.
Cust delivered a two-run single in a six-run third inning against Rangers starter Ismael Valdes.
Valdes surrendered six runs and seven hits in 2 2/3 innings while Ryan Drese was reached for four runs and six hits in two frames.
Ryan Christenson had two hits and scored twice and Donnie Sadler and Ruben Sierra each produced two RBI for Texas.