Nick Hundley homered, Chris Davis had a two-run double and Adam Jones and Delmon Young also drove in runs for the Orioles.
Tillman (10-5) matched a career high with nine strikeouts, giving up one run and three hits. He won for the third time this month as Baltimore improved to 38-26 away from Camden Yards.
Tillman's lone mistake came in the first when he allowed Jose Abreu's 32nd home run, tying the Orioles' Nelson Cruz and Miami's Giancarlo Stanton for the most in baseball. The homer was Abreu's first of the month.
Jose Quintana (6-10) who lost his third straight start.
