That, as the defendant conceded at oral argument, there was sufficient evidence for submission to the jury at the close of the defendant’s case, in this automobile tort action, vitiates his motion for a directed verdict made at the close of the plaintiffs’ case on the ground that the evidence was then insufficient. “[I]f a party introduces evidence after making an unsuccessful motion for a directed verdict at the close of his opponent’s case, this constitutes a waiver of the objection to the sufficiency of the evidence.” Martin v. Hall, 369 Mass. 882, 884 (1976).

Judgments affirmed.