All-stars Carter McEachern and Jared James each had two hits and an RBI on Thursday to lead the Thunder By Border Cats back into the win column.
James homered on a 3-1 count to lead off the third inning, his fourth round-tripper of the summer. He later doubled and scored again.
The Cats built a 5-0 lead, then held on in the eighth and ninth as the visiting Wisconsin Rapid Rafters battled back to score three and close the gap to what would prove to be the final 5-3 score.
Thunder Bay starter Zach Thiac was strong, giving up just three hit in seven innings of shutout baseball. He was credited with the win.
Shortstop Matt Batten had three hits and drove in one for the Border Cats.
The two teams meet again on Friday night at Tbaytel Park at Port Arthur Stadium.