The Loons held on to a 1-0 lead for a majority of Monday night??s game to defeat the West Michigan Whitecaps.
Pedro Guerrero had an RBI double in the third inning, sending Pratt Maynard to home plate and giving the Loons the only run in the game.
Maynard originally singled to right field, and reached second base thanks to a sacrifice bunt by Jeff Hunt.
Raydel Sanchez gave up no runs or hits through seven innings in his second win of the season, and his longest outing as a Loon. Michael Thomas came in relief of Sanchez and pitched the eighth inning, while Yimi Garcia got the save in the ninth.
Singles by Brandon Loy and Luis Castillo in the eighth were the only two singles for the Whitecaps in the game.
Great Lakes improves to 5-6 since the All-Star break, and 39-42 overall. The decisive game for the series will be Wednesday night, as the Loons try to win their first series against West Michigan since mid-May.