The Twins defeated the Pittsburgh Pirates 4-3 Monday afternoon in their final exhibition game in Florida this season.  Danny Lehmann had a walk-off single in the 9th inning to plate the winning run.  Francisco Liriano threw 6 innings with 4 hits and 3 earned runs allowed for Minnesota.  The Twins are 19-11 and will play at Atlanta at 6:05 tonight, pregame on WJON at 6:00.  Minnesota begins the regular season Friday night at Toronto at 6:07, pregame on WJON at 5:35.  The Twins also traded minor league pitcher Billy Bullock to Atlanta for the right to retain rule 5 draft pick Scott Diamond.  Diamond allowed 1 earned run in 6 innings while pitching in exhibition games for the Twins but was limited with a blister on his left thumb.