For a half, USF couldn't hang onto the basketball.
In the second half, the Bulls failed to keep Notre Dame off the free-throw line, where the Irish were deadly.
Put together, USF was only rarely in contention in a 62-55 Big East loss Wednesday before 10,188 at the Joyce Center.
"It's very frustrating," USF forward Solomon Jones said. "It was so close and we're not able to pull one out."
USF (6-18) fell to 0-11 in the conference with five regular-season games left and are riding a school-record 13-game losing streak.
"We have to keep fighting and hopefully pull one out sooner or later," Jones said.
Jones finished with his 11th double double of the season with 13 points and 12 rebounds.
"I feel like, even though I had that, I didn't play that well tonight," Jones said. "It doesn't mean anything because we didn't get the win."
USF led for the first nine minutes, but from an 11-6 deficit Notre Dame went on a 19-2 run and did not trail again.
Then turnovers began to hurt USF.
Notre Dame didn't convert on every turnover, though it seemed that way. The Irish scored 22 off 15 Bulls turnovers in the game.
The punishment was most extreme in the first half, when Notre Dame scored 18 off 11 turnovers. The Bulls, by contrast, scored zero off six Notre Dame turnovers.
"We had 15 turnovers for the game and we'll take that," USF coach Robert McCullum said. "It's when they happen. We were down 12 points at halftime, and they scored 18 off our turnovers. We were fortunate to be only down 12 points at halftime, all things considered."
Notre Dame hit only seven field goals in the second half but maintained its margin thanks to a series of trips to the line. The Irish hit 20 of 29 free throws in the game, 17-of-25 in the second half.
"I think that's an example that they were the more physical team," McCullum said. "They have a lot of options and a lot of weapons offensively."
USF struggled to get a rally started in the second half. Twice inside the final five minutes, the Bulls trailed by eight. A late flourish cut Notre Dame's lead to 61-55 with 13 seconds left.
James Holmes scored 12 of his 18 in the second half and added 12 rebounds for the Bulls.