Bowsher's Justin Neptune hit a 3-pointer with just over a minute left to break a 66-66 tie and later added a free throw - his fourth and final point - as the Rebels beat Whitmer 74-69 on the road.
Robert Davis paced Bowsher with 29 points, and Troy Huebner and Eric Daniels added 13 and 11, respectively.
The Rebels (4-5, 1-3) made 14 of 16 free throws in the second half, while Whitmer (6-3, 2-2) made just 8 of 16.
For the game, Bowsher converted 25 of 32 from the line.
For Whitmer, Dareon Jones scored 17 points, Randall Kennedy 11, and Kenny Hayes 10.
Storm Stanley scored 24 points and pulled down eight rebounds as St. Francis prevailed at home.
Kent Goldsmith added 16 points and six assists for the Knights (6-3, 3-1). For Scott (1-7, 0-4), Austen Acabata poured in 23 points. The Knights led 28-17 at halftime.
The Spartans led by 13 at the half, and then opened the third quarter with a 13-0 run to put the game away.
Start used a 22-6 scoring advantage in the third quarter to pull out to a 69-40 lead with a period to play.
Anthony Henderson had 32 points to lead Start, while Jeff Copeland and Fred Morris added 14 each, Robert Wietrzykowski had 13 and James Gray scored 10.
Morris added 10 rebounds for Start. Clay was paced by Taylor Shabel with 32 points.
The Cowboys claimed the home victory as five players scored in double figures.
Milan Mabry led the scoring parade with 17 points, Chris Lawson added 15, Maurice Birdsong 12, Maurice Taylor 11 and Lonacy Utley 10. Utley also grabbed 12 rebounds for Libbey (6-2 overall, 3-1 City).
For the Polar Bears, Ray Hooker took scoring honors with 19 points and Brandon Wyatt added 15.