A ninth-inning collapse cost the Border Cats another check mark in the loss column.
The host Mankato MoonDogs, held off he score sheet for six innings, scored five times in their final at bat and walked away with a 9-8 victory to send the Cats (12-16) to their sixth loss in seven games.
Reliever Mikael Mogues, Thunder Bay's every-day first baseman, gave up four hits and three runs in the decisive inning, the winning run coming home on a Kevin Hall single as the MoonDogs (15-14) batted around.
The Cats led 5-4 heading into the ninth and scored three runs to open up a four-run advantage.
Jared James had three hits in five trips to the plate for Thunder Bay, scoring twice. Nate Nolan had a pair of RBI on a Cats team that rapped out 14 hits, chasing Mankato starter Rhett Rapshus in the fifth, having scored four times.
Thunder Bay starter Johnny York tossed seven innings of three-hit ball, but was let down by his bullpen. Reliever Donnie Sellers gave up a pair of runs on three hits in a third of an inning of work. Julian Loret de Mola also gave up two runs in his one-inning appearance.
Mogues was tagged with the loss, his first. Kyle Goodbrand got the win, despite giving up three runs – just one of them earned.
The Border Cats return home Thursday night to take on the Rochester Honkers (17-11).