Jerian Grant scored 18 points and Knight had 17 as No. 24 Notre Dame beat South Florida 73-65 on Saturday.
Knight, a 6-foot-10 senior, made the most of his chance as the Fighting Irish played without sixth-year forward Scott Martin, who is out indefinitely with a bad left knee. Knight had appeared in just 12 of Notre Dame's first 19 games this season.
"I would have been shocked if he didn't play well," Notre Dame coach Mike Brey said. "He's been around us for a while, so it's nice. You lose a six-year senior and we put in another senior who's been in our program. Certainly helped us."
Knight had never scored in double digits before, with his previous best being nine points against Sacred Heart on Dec. 19, 2011. He made 8 of 10 shots and pulled down seven rebounds Saturday.
"He's just playing with confidence right now." Grant said of Knight. "A lot of people knew he had it. He's knocking down shots, rebounding, blocking shots, so it's definitely something we need the rest of the year."
Eric Atkins added 13 points and Pat Connaughton contributed 12 for Notre Dame (16-4, 4-3 Big East), which had lost three of four, including a 63-47 loss to Georgetown last Monday.
Notre Dame forward Jack Cooley, who entered averaging 14.8 points, finished with six points and 14 rebounds.
Notre Dame used a 20-3 run to go ahead 48-40 with 13 minutes to play. Connaughton's 3-pointer broke a 40-all tie before Knight dunked and Grant connected on a 3 to make it 48-40.
"Sometimes I like to get up there and show (our coaches) I can," Knight said. "It was nice to do that. And the dunk was obviously fun, too."
South Florida got within 52-48 midway through the second half on LeDay's basket. Notre Dame responded by scoring the next six points, a three-point play by Grant and a 3-pointer by Atkins. Victor Rudd gave South Florida a 37-28 lead with a dunk on the first possession of the second half.
"A very good offensive team," South Florida coach Stan Heath said of Notre Dame. "They're very skilled. Know how to play. Once they got momentum going second half, we just couldn't get it back." Notre Dame outrebounded South Florida 34-17.
Collins had 10 points as South Florida grabbed a 35-28 halftime lead. The point guard's three-point play tied it at 28 4 minutes before intermission.
"I'm thrilled ... that's a great win for us," Brey said. "We've been struggling. I'm very proud of our group because at halftime, we could have thought, `Maybe not today down here in Tampa." Toarlyn Fitzpatrick hit a long-range jumper, Javontae Hawkins had a tip-in and Rudd made a jumper that put the Bulls up 35-28 in the final minute of the half.
Notre Dame took a 24-18 lead on Connaughton's rebound basket with 8 minutes left in the opening half. The Fighting Irish failed to score during the first-half's final 5 minutes.