The victory gave Broncos' coach Steve Hawkins his 300th career win. Nate Hutcheson added 11 for Western Michigan (4-1).
"I truly did not know it until it happened ... when I started I was skinny and had hair," the bald-headed Hawkins said. "The most important thing, we've got a lot of freshmen, and to get the win, to reward the kids for a great effort was the most important thing."
"We've got to be more consistent," Noriega said. "That's been a big issue for us."
Both teams won games Friday and Saturday in the three-day South Florida Invitational.
Jared Klein converted a 3-pointer to give Western Michigan a 55-50 lead with three minutes to go. Jawanza Poland's three-point play cut the USF deficit to 55-53 with just two under minutes remaining, then Hutcheson's late three-point play made it 58-53.
South Florida grabbed a 46-45 lead when Noriega made a 3-pointer and added a three-point play midway through the second half.
"We've got to become a better team at finishing," South Florida coach Stan Heath said. "We were very good at that in the past."
Paul connected on a 3-pointer as Western Michigan went ahead 43-38 with 13 1-2 minutes left.
Fitzpatrick had 12 points to help South Florida take a 36-34 halftime lead. The senior forward made his fourth 3-pointer of the half and Zach LeDay had a slam to put the Bulls ahead 32-25 three minutes before the break.
"We had a chance to really buckle when South Florida took a seven-point lead there," Hawkins said. "I thought that was the critical point in the game."
Pokley hit a pair of long-range jumpers as Western Michigan took an early 10-5 lead. South Florida, keyed by three 3-pointers by Fitzpatrick, went ahead 13-12 six minutes into the game.
Western Michigan outrebounded USF 39-26.