ACC player of the year Seth Beer and Weston Wilson also homered as the sixth-seeded Tigers (40-18) improved to 2-0 at the round-robin tournament.
Both of Rohlman's homers were solo shots. One tied it at 3 in the fifth, and the other broke the tie in the sixth.
Beer added a bases-empty shot with one out in the seventh, giving him a league-leading 16 — a school record for freshmen.
Clate Schmidt (8-4) struck out six in 8 2-3 innings but allowed consecutive singles with two outs in the ninth. Reliever Pat Krall got Corey Ray to line out and preserve the victory.
Danny Rosenbaum and Colin Lyman had two hits and an RBI apiece for the second-seeded Cardinals (47-11). They fell to 1-1 in pool play.