O’Sullivan pitched 10 2/3 innings last week, tallying a 1-0 record with a 0.84 earned run average and 15 strikeouts to help the third-ranked Warhawks to a pair of wins and a share of the WIAC regular season championship. On Wednesday in UW-Whitewater’s second game at UW-Eau Claire, he allowed one run on five hits with no walks and 10 strikeouts, his fifth double-digit strikeout performance of the season, to help the Warhawks to an 11-1 victory. On Sunday at UW-Oshkosh, O’Sullivan tossed 2 2/3 scoreless innings in relief, striking out five, as UW-W secured a 7-6 triumph in 13 innings.