Judgment, Supreme Court, New York County (Daniel P. FitzGerald, J.), rendered December 4, 1989, convicting defendant, after a jury trial, of criminal possession of a controlled substance in the third degree, and sentencing him, as a predicate felon, to an indeterminate term of imprisonment of from 5 to 10 years, unanimously affirmed.
Contrary to the defendant’s contentions, the record reveals that the trial court weighed the probative worth of the evidence against the risk of unfair prejudice and permissibly concluded that the prosecution should be permitted to inquire into the facts underlying the defendant’s prior drug sale. *272(People v Sandoval, 34 NY2d 371.) The evidence was probative of the defendant’s willingness to place his interests above those of society, and was particularly probative on the issue of credibility. (People v Aiken, 162 AD2d 106, lv denied 76 NY2d 851.) Furthermore, that the defendant was the only material source of testimony in support of his defense, while relevant, is but one factor to consider in determining whether inquiry should be permitted into a prior conviction. (People v Sandoval, supra, at 378.) Concur—Sullivan, J. P., Milonas, Asch, Kassal and Smith, JJ.