Appeal from an order of the Supreme Court, Monroe County (Harold L. Galloway, J.), dated March 18, 2005. The order granted defendant’s motion for summary judgment dismissing the complaint in a personal injury action.
It is hereby ordered that the order so appealed from be and the same hereby is unanimously affirmed without costs.
Memorandum: Plaintiff commenced this action seeking damages for personal injuries suffered by her son, Sean, when he allegedly fell off the roof of the East Rochester Middle School gymnasium. We conclude that Supreme Court properly granted defendant’s motion for summary judgment dismissing the complaint. In support of her contention that the court erred in granting defendant’s motion, plaintiff relies exclusively on a theory of negligence raised for the first time in opposition to defendant’s motion. Inasmuch as “[a] plaintiff cannot defeat an otherwise proper motion for summary judgment by asserting a new theory of liability for negligence for the first time in opposition to the motion,” plaintiff’s reliance on that theory of negligence is misplaced (Winters v St. Vincent's Med. Ctr. of Richmond, 273 AD2d 465, 465 [2000]; see Harrington v City of New York, 6 AD3d 662, 663 [2004]; Araujo v Brooklyn Martial Arts Academy, 304 AD2d 779, 780 [2003]; Matacale v County of Steuben, 289 AD2d 949, 950 [2001]; Yaeger v UCC Constructors, 281 AD2d 990, 991 [2001]). Defendant established its entitlement to judgment as a matter of law by establishing that the sole proximate cause of Sean’s injuries was Sean’s “own willful behavior in engaging in hazardous and illegal conduct, and *882compensation should not be granted in such circumstances” (Tillmon v New York City Hous. Auth., 203 AD2d 19, 20 [1994]; see Boltax v Joy Day Camp, 67 NY2d 617 [1986]; Pytel v New Jersey Tr. Auth., 267 AD2d 155 [1999]; Gustin v Association of Camps Farthest Out, 267 AD2d 1001, 1002 [1999]). Present— Pigott, Jr., P.J., Green, Kehoe, Martoche and Pine, JJ.