—Appeal from a judgment of Supreme Court, Erie County (Michalek, J.), entered August 15, 2001, which dismissed the complaint upon a jury verdict in favor of defendants.
It is hereby ordered that the judgment so appealed from be *1008and the same hereby is reversed in the exercise of discretion with costs and a new trial is granted.
Memorandum: Plaintiff appeals from a judgment dismissing her complaint following a jury verdict in favor of defendants. Plaintiff commenced this medical malpractice action against defendant Children’s Hospital of Buffalo (Hospital) and various doctors and Hospital personnel seeking damages for injuries allegedly sustained by her daughter during labor and delivery on August 20, 1986. At birth, plaintiff’s daughter was diagnosed with perinatal asphyxia, meconium aspiration, persistent fetal circulation, and seizures. By the time of trial, plaintiff’s daughter was 14 years old and suffered from moderate mental retardation, cortical blindness, a seizure disorder, and motor disabilities. Plaintiff alleged that her daughter’s injuries were caused by defendants’ failure to induce labor when her daughter was in fetal distress.
Plaintiff contends that Supreme Court erred in permitting the Hospital and its personnel to present expert testimony that the injuries sustained by her daughter were caused by an intrauterine infection resulting from the Coxsackie virus. We disagree with plaintiff that the court abused its discretion as a matter of law in permitting that expert testimony. CPLR 3101 (d) (1) (i) specifically permits the late retention of an expert upon good cause shown. The Hospital disclosed the expert three weeks before trial and the disclosure was made contemporaneously with plaintiff’s disclosure of expert testimony. Moreover, the record contains no evidence of willfulness.
Nevertheless, in the exercise of our inherent power to vacate a judgment, we conclude that plaintiff should be granted a new trial because she was unfairly confronted with defendants’ new and highly complex defense on the eve of trial. Indeed, we conclude that plaintiff was unduly prejudiced by defendants’ failure to provide her with sufficient information concerning the nature of the test underlying that defense in a timely manner, and thus she was unable to conduct an effective cross-examination of defendants’ expert witness, who testified to his conclusions with 100% degree of certainty. While the verdict sheet supports the position of the dissenters that the jury found that defendants did not deviate from accepted medical practice and that the jury did not address the issue of causation, we do not believe that the two issues can be treated separately under the facts of this case. We note that defendants’ attorneys each asserted on summation that plaintiffs daughter was infected before plaintiff came to the Hospital or was treated by defendant doctors and Hospital personnel. The attorney for defendants Bryant Street Anesthesiologists, P.C. (Bryant Street) and Max Richard Chudy, III, M.D. and the attorney for the *1009Hospital and its personnel highlighted the evidence that plaintiff took an antibiotic and vitamin C while she was pregnant, asserting that the evidence established that she was fighting an infection. Moreover, the attorney for Bryant Street and Chudy asserted that plaintiff’s experts did not conduct the test to detect the Coxsackie virus “[bjecause they might get the same results.” Because defendants’ attorneys asked the jury to find that the Coxsackie virus caused the injuries to plaintiff’s daughter and that defendants therefore were not negligent, we conclude that the jury likely did not separately resolve the inextricably intertwined issues of negligence and causation.
We have considered plaintiff’s remaining contentions and conclude that they are without merit. Consequently, we reverse the judgment in the exercise of our discretion (see generally International Sys. v Delcrete Corp., 103 AD2d 1008), and grant a new trial.
All concur except Hurlbutt and Kehoe, JJ., who dissent and vote to affirm in the following memorandum.