"I knew it was going in," said Knowles, a senior guard from Antioch, Calif. "I have confidence in my shot even though I've been struggling."
Cabrini (31-1) won its 22nd straight game to advance to the championship for the first time. The Pennsylvania school will face Wisconsin-Whitewater in the final Saturday night. Whitewater beat MIT 71-56.
Illinois Wesleyan (23-8) tied it at 78 on Stephen Rudnicki's jumper with 13.4 seconds remaining. Cabrini called a timeout, and Aaron Walton-Ross drove down the lane before finding the open Knowles in the corner.
"The play was actually designed to leave his hand and then the buzzer go off not with 5 seconds left," Cabrini coach Marcus Kahn said, laughing. "We wanted to make sure we had the last shot at it. It worked how we wanted it to work. Some people may wonder did we want to get it to Knowles? Yes, he can shoot."
Illinois Wesleyan's Eliud Gonzalez came up short on a long jumper at the buzzer.
John Boyd led Cabrini with a career-high 34 points, scoring 24 points in the first half. He hit seven 3-points and was 13 of 22 from the field.
Cory Lemons and Fran Rafferty each had 11 points, and Knowles finished with seven points - six in the final 3:37. Cabrini was 13 of 25 from 3-point range.
"We are gritty," Kahn said. "We have an edge about us. That's why we are here. It's that simple. I'd love to tell you it's all that genius work we do in the office. But it's about good players who play together and play hard and know how to win."
Jordan Zimmer topped Illinois Wesleyan with 19 points.
Cabrini trailed by nine with 6:58 remaining. But the Cavaliers switched to a pressing defense, and that led to 12-1 run in which they took a 76-73 lead on Fran Rafferty's layup with 2:53 remaining.
"I told our team, 'This is when we are at our best,'" Kahn said. "When things aren't going our way, we stick together and we play harder."
The Titans came back, tying it at 76 on a free throw by Andrew Ziemnik with 1:07 to go. Knowles' layup with 35 seconds left gave Cabrini a 78-76 lead, and Illinois Wesleyan tied it on Rudnicki's jumper.
"I give Cabrini credit," Illinois Wesleyan coach Ron Rose said. "They started pressing and putting pressure on the ball. That changed the game. In the beginning of the second half, they started pressing and took us out of our rhythm. Give Cabrini credit. They felt the game slipping away, and they became the aggressor."
