— Order, Supreme Court, Bronx County (Herbert Shapiro, J.), entered on or about August 10, 1989, which set aside a jury verdict assessing defendant 100 percent liable and directed a new trial, is affirmed, without costs.
*795In this personal injury action, plaintiffs decedent, Expedito Aragonés, who died in 1989 of unrelated causes, fell between two cars of a moving subway train on May 3, 1984, and sustained injuries that necessitated the amputation of three fingers on his left hand. Following a bifurcated trial in which the jury determined solely the issue of liability, a verdict of 100 percent liability was returned against defendant, the New York City Transit Authority. Plaintiff appeals from an order of the trial court setting aside the verdict pursuant to CPLR 4404 (a), as against the weight of the evidence, and directing a new trial. We affirm.
A motion to set aside the verdict as contrary to the weight of the evidence requires a determination that "the jury could not have reached its verdict on any fair interpretation of the evidence” (Delgado v Board of Educ., 65 AD2d 547, affd 48 NY2d 643). A trial court’s grant of such relief is a discretionary act requiring the balancing of many factors (Cohen v Hallmark Cards, 45 NY2d 493, 499) and, as noted by Justice Lazer in Nicastro v Park (113 AD2d 129, 137), must be "view[ed on appeal] with liberality * * * not only because the trial court is in the best position to properly assess the evidence presented at trial, but also because judicial independence of mind in making that determination is an essential 'ingredient to the sound health of the judicial process’ [citations omitted]”. This discretionary power must, however, be exercised with a great deal of caution, and may not be employed simply because the trial court disagrees with the verdict, as this would "unnecessarily interfere with the fact-finding function of the jury to a degree that amounts to an usurpation of the jury’s duty” (Ellis v Hoelzel, 57 AD2d 968, 969).
With these principles in mind, we have reviewed the record before us, and conclude that there was no abuse of discretion in the trial court’s setting aside of the verdict. Although, as noted by our dissenting colleague, this case presents conflicting testimony, and therefore involves the credibility of witnesses, great respect should be accorded to the trial court’s exercise of discretion by a reviewing court, in light of the trial court’s opportunity to hear and see the witnesses testify, as well as to observe courtroom events that may affect the jury’s evaluation of the evidence (Nicastro v Park, supra, at 137; see, Siegel, NY Prac § 406; 4 Weinstein-Korn-Miller, NY Civ Prac ¶ 4404.06). Concur—Sullivan, J. P., Wallach and Kassal, JJ.