Leach (2-0) allowed the Hammerheads' lone hit en route to the win after striking out four batters over five shutout innings. Colla and Boleska added two strikeouts apiece, while Krol took Jupiter's Jake Smolinski down swinging in the ninth for the Marauders' ninth strikeout of the game.
Bradenton's pitchers stranded six Hammerheads on the day.
Left-handed batters are only hitting .167 against Leach this year. A 25th-round pick in 2008, Leach held South Atlantic League hitters to a .221 batting average last season while posting a 2.96 ERA.
With two scoreless innings of relief, Colla reduced his ERA to 1.50. While opponents are hitting .313 against the former Arizona Wildcat, he has yielded only one run.
Krol has given up two runs -- one earned and one unearned -- this year, but the Wichita State product has held opponents to a .158 batting average.
Boleska bounced back from a rough outing last Thursday with a solid inning of relief. The Montreal native yielded three earned runs the last time he took the hill, but struck out two and didn't allow a baserunner Monday.