The defendant appeals from her convictions of operating a motor vehicle while under the influence of intoxicating liquor, G. L. c. 90, § 24(l)(o)(l), and of negligent operation of a motor vehicle, G. L. c. 90, § 24(2)(a). We conclude that her trial attorney’s failure to object to hearsay testimony constituted ineffective assistance of counsel, and we remand the case for a new trial.
On July 22, 2003, at 3:00 a.m., Mansfield police Officer Paul Whitty arrived at the scene of a single-car rollover accident on Route 106 in Mansfield. Three people, including the defendant, were seated on the curb. One of the three, Brandon Travis, im*583mediately approached the officer and told him that he (Travis) had been driving at the time of the accident. After Travis failed a series of field sobriety tests, the officer arrested him. At that point, the defendant, the registered owner of the car, approached the officer and told him that she had been operating the vehicle. The defendant also failed field sobriety tests.
The officer asked Ryan Hitchcock, the third person, if he knew who had been operating the car. Hitchcock responded that he was “ninety percent sure” the defendant was driving, because he remembered her saying she wanted to drive. The officer then arrested the defendant and placed Travis in protective custody. The officer testified that after he arrested the defendant, Travis told him: “I want to take the rap.”
At trial, the officer repeated Hitchcock’s “ninety percent” statement without objection. Also without objection, the officer testified that in his opinion the defendant had been the driver of the car. Hitchcock did not testify.
Travis testified that he, Hitchcock, and the defendant were returning to his home after dropping off two friends, Kelly Mc-Dougall and John Nogler, at McDougall’s home. McDougall testified that Travis was driving as the car left her home. Travis and the defendant testified that Travis was driving the car when the accident occurred.
The defendant’s admission would not be enough to warrant a finding by the jury on the element of operation without some corroborative evidence that she was the driver. See Commonwealth v. Forde, 392 Mass. 453, 457-458 (1984); Commonwealth v. Adams, 421 Mass. 289, 291 (1995). Hitchcock's “ninety percent” statement provided the necessary corroboration of the defendant’s confession1; but for its probative force, the defendant would have been entitled to a required finding of not guilty.2 Compare Commonwealth v. Frisino, 21 Mass. App. Ct. 551, 555-556 (1986).
*584The “ninety percent” statement, made out of court and offered for the truth of its contents, was inadmissible as hearsay not subject to any exception. See Commonwealth v. Keizer, 377 Mass. 264, 269 n.4 (1979). See generally Young, Pollets, & Poreda, Evidence § 801.3 (2d ed. 1998). Trial counsel’s failure to object to its admission allowed a previously legally insufficient case to go to the jury and deprived the defendant of a required finding of not guilty.3 Compare Commonwealth v. Frisino, 21 Mass. App. Ct. at 555-556. This is not a case where “better work might have accomplished something material for the defense” (emphasis supplied), Commonwealth v. Satterfield, 373 Mass. 109, 115 (1977); here, “trial counsel held, but never played, the highest trump.” Commonwealth v. Frisino, 21 Mass. App. Ct. at 555.
*585Although a claim of ineffective assistance is usually best resolved in the first instance by the trial judge on a motion for a new trial, see Commonwealth v. Adamides, 37 Mass. App. Ct. 339, 344 (1994), where, as here, the existing record clearly shows the deficiency in the Commonwealth’s case, such a motion is unnecessary. See Commonwealth v. Frisino, 21 Mass. App. Ct. at 556; Commonwealth v. Adamides, supra. Unlike Frisino, judgments for the defendant are not warranted in this case, because the Commonwealth could potentially produce Hitchcock as a witness in a new trial.
Judgments reversed.
Verdicts set aside.