Chattanooga never got the chance to rally for a second consecutive win over Birmingham as rain halted the game after seven innings Sunday and the Lookouts lost 5-2.
The Barons jumped on Lookouts starting pitcher Zach Lee with three first-inning runs, as Marcus Semien had a double to left, Trayce Thompson an RBI triple to right and Dan Black a two-run home run to right.
They extended their advantage to 5-0 in the third inning on RBIs by Black and Brandon Jacobs before the Lookouts (12-16) got two back in the fourth when Sean Burroughs doubled to right to score Rafael Ynoa and Brian Cavazos-Galvez.
Game five of a five-game series in Birmingham is Monday at 8:05 EDT.
Ross Stripling (5-1, 2.73) is scheduled to start for the Lookouts, with Scott Snodgrass (9-7, 4.43) scheduled for the Barons.