With a 3-0 afternoon victory Wednesday at Birmingham, Chattanooga became the first Southern League team to win 20 games this season.
Lookouts pitcher Jose Berrios allowed two hits in nine innings and struck out eight to improve to 4-1 and lower his earned run average to 2.60.
Berrios got all the run support he needed in the second inning, when Max Kepler and Adam Walker had RBI doubles to center field. Kepler scored on the hit by Walker, who came in on a Heiker Meneses single to left to give the Lookouts (20-13) their 3-0 lead.
Game five of the six-game series in Birmingham is tonight at 8:05 EDT. Greg Peavey (2-1, 8.89 ERA) is the scheduled starting pitcher for the Lookouts, with Frankie Montas (0-0, 3.00) scheduled for the Barons.