We affirm appellant’s conviction and sentence. Although we agree with appellant that the trial court erred in allowing a prosecution witness to be impeached, we find such error to be harmless beyond a reasonable doubt. State v. DiGuilio, 491 *897So.2d 1129 (Fla.1986). Our conclusion is mainly predicated upon the admission of other substantial evidence concerning the witness’ prior identification of the appellant as his assailant.
HERSEY, C.J., and ANSTEAD and WARNER, JJ., concur.