An All-Star last season, Duke is likely to start for the Pirates on opening day. He gave up one run and two hits in this one before Pittsburgh rallied for its first win of the spring.
Adam Jones hit a solo home run off Daniel McCutchen, trying to win a spot in the Pirates' rotation. It was the Orioles' ninth home run in three games.
Baltimore's Chris Tillman worked two perfect innings in his first spring start.
Pittsburgh trailed 3-2 going into the eighth but tied it on Tony Sanchez's first home run. Sanchez was the fourth overall pick in the 2009 amateur draft.