I had to go look it up. SU's media guide isn't as good as orangehoops, but they've got Dennis Duval with 30 once (that's the school record for makes, too - 18) and Demetris Nichols with 27 against UConn in 2006.
I remember being at that game and realizing how badly Nichols was overmatched by Rudy Gay and how badly McNamara, as usual, was overmatched by every Connecticut guard. Checking orangehoops, Nichols made 9 of the 27 shots he took (and McNamara had one of those 5-16 nights). Not good, but better than 8-30.