The Orioles got back-to-back singles from No. 9 hitter Robert Andino -- which scored Paulino -- and Nolan Reimold. J.J. Hardy's sacrifice fly scored Andino to give the Orioles a 5-0 lead.
"I love being aggressive on the bases," Davis said. "Anytime you can put pressure on the other team to make a play, it's really playing into your hands, and we were able to catch a few breaks. The conditions weren't good for throwing the baseball tonight, so we were very aggressive, and it paid off for us."
The Orioles battered Ross (1-1), who allowed nine runs on 11 hits, both career highs, in four-plus innings of work, hurting an AL-best 2.68 team ERA for Oakland (11-11) heading into the night.
Betemit added an RBI double in the third inning, and Jones' third hit of the night -- a run-scoring single in the fifth -- put the Orioles up 7-0. That was followed two batters later by a two-run single by Davis, who also had three hits on the night.
Chen gave way to right-hander Luis Ayala, who pitched two scoreless relief innings, allowing just one hit.