In a matrimonial action, defendant appeals from an order of the Supreme Court, Suffolk County (Geiler, J.), dated September 28, 1981, which denied his motion to set aside (1) a judgment of divorce entered July 21, 1980, and (2) a stipulation of settlement, dated February 4, 1981, relating, inter alia, to the division of certain property which had been jointly owned. Order reversed, on the law, without costs or disbursements, and matter remitted to Special Term for a hearing in accordance herewith. The pertinent facts and proceedings are set forth in the memorandum of our colleague, Justice Presiding Mangano. In brief summary, defendant husband seeks to vacate a judgment of divorce on the ground that the judgment was fraudulently obtained by the plaintiff wife without opposition from defendant, by lulling him into believing that the parties might reconcile. According to his motion papers, defendant was served in May or June of 1980 with a summons. After receiving the summons, defendant contacted the plaintiff to discuss the divorce action, and the parties decided to attempt a reconciliation. With this in mind, the parties went to Barbados. During their stay in Barbados and, according to defendant, unbeknownst to him, a final judgment of divorce was granted to the wife on July 16, 1980 and entered on July 21, 1980, on the ground of cruel and inhuman treatment. While not setting forth in his 'motion papers the nature of any defenses he may have to the divorce complaint, defendant requested permission to interpose an answer. On February 4, 1981, defendant, still unrepresented by counsel, entered into a “stipulation of settlement” concerning, among other things, the partition and division of certain real property. As detailed at length in Justice Presiding Mangano’s memorandum, defendant alleges that this agreement was the product of overreaching or fraud on the part of plaintiff and her attorney. We concur with our dissenting colleague that a hearing is needed to resolve the question of whether the stipulation of settlement should be set aside as the result of overreaching or fraud on plaintiff’s part. We disagree with the view, however, that defendant is not entitled to a hearing to determine whether the judgment of divorce should be vacated. A recital of precedent is hardly necessary to support the maxim that a default judgment will ordinarily not be vacated absent a showing that there exists a reasonable excuse for the default and that the party in default possesses a meritorious cause of action or defense. This rule applies in matrimonial actions, albeit circumspect consideration is necessary in that context (see Levy v Levy, 67 AD2d 998). However, defendant’s motion to vacate the judgment of divorce is not brought on the ground of excusable default as delineated in CPLR 5015 (subd [a], par 1). Rather, his motion to vacate, being predicated on an accusation that he was lulled into a false sense of security with respect to the divorce action, in essence an allegation of extrinsic fraud (see Tamimi v Tamimi, 38 AD2d 197), is brought pursuant to CPLR 5015 (subd [a], par 3). That paragraph allows a judgment to be vacated upon the ground of “ ‘fraud, misrepresentation, or other misconduct’ ” (see Oppenheimer v Westcott, 47 NY2d 595, 603). In our opinion, a movant seeking relief from a judgment under this paragraph, at least on the ground of extrinsic fraud, need not show that he has a meritorious defense or cause of action. Extrinsic fraud may be defined as a fraud practiced in obtaining a judgment such that a party may have been prevented from fully and fairly litigating the matter (see Tamimi v Tamimi, supra, and authorities cited therein). While it certainly could be said that extrinsic fraud is a ground for excusing a default, the Legislature has distinguished it from other grounds which serve as bases for *404excusing defaults (CPLR 5015, subd [a], par 1). Likewise, a failure to be properly served with process might be considered a reasonable excuse, justifying the vacatur of a default. Nonetheless, the Legislature has set aside a distinct paragraph for such motions (see CPLR 5015, subd [a], par 4). In fact, the Legislature has gone so far as to create a special subdivision allowing an administrative judge to bring a proceeding to vacate default judgments era masse where “obtained by fraud, misrepresentation, illegality, unconscionability, lack of due service, violations of law, or other illegalities” (CPLR 5015, subd [c]; see Judiciary Law, former § 217-a). There is a good reason to treat motions to vacate default judgments differently, dependent on whether extrinsic fraud, lack of jurisdiction, or some other ground is alleged. Nowhere is this clearer than in the case of a lack of proper service. Absent proper service, a default judgment is a nullity, and, once it is shown that there was no service, the judgment must be unconditionally vacated (see McMullen v Arnone, 79 AD2d 496). Whether or not the defendant has a meritorious defense is irrelevant to the question of whether the judgment should be vacated for a lack of jurisdiction (Pine v Town of Hoosick, 56 AD2d 692; Queensboro Leasing v Resnick, 78 Misc 2d 919). The existence of a meritorious defense only becomes significant in determining whether to open a default once it is clear that service has properly been made (Mayers v Cadman Towers, 89 AD2d 844). A judgment obtained without proper service of process is invalid, even when the defendant has actual notice of the lawsuit, because as a prophylactic measure such a rule is necessary to prevent “sewer service” (see Feinstein v Bergner, 48 NY2d 234, 239-241). “Sewer service” is, however, but one species of fraud that the Legislature and courts are concerned with vis-á-vis invalid default judgments. Extrinsic fraud, which includes the touting of someone away from the courthouse, to prevent any possibility of an adverse result, is another (Siegel, Supplementary Practice Commentaries, McKinney’s Cons Laws of NY, Book 7B, CPLR 5015, p 365, 1964-1982 Supp Pamph). In fact, from a policy point of view, there is little if any difference between a default judgment obtained by “sewer service” and one obtained where the defendant might be properly served, but then, through some device, trick, or deceit, is led to believe that he or she need not defend the suit. Both are frauds on the court and on the defendant (see Matter of Holden, 271 NY 212, 218). It is not surprising, therefore, that a judgment obtained through extrinsic fraud, like one obtained without proper service, is considered a nullity (Tamimi v Tamimi, 38 AD2d 197, supra). The court will have no part in enforcing a judgment which was procured by a fraud practiced on it (Matter of Holden, supra). The inescapable conclusion, in our view, is that, just as in the case where there is improper service or no service, a default judgment obtained through extrinsic fraud should be vacated without any requirement that the movant show a meritorious defense. Such a judgment is a nullity, irrespective of the question of merit. One other contention in the partial dissent requires discussion. It is argued that, quite apart from whether defendant’s moving papers were deficient because they did not set out any meritorious defense, “defendant should be estopped from attacking the underlying divorce judgment”. The present record does not support a finding of estoppel, since there is no evidence that plaintiff has been prejudiced by virtue of defendant’s conduct subsequent to his learning of the divorce judgment (see Nassau Trust Co. v Montrose Concrete Prods. Corp., 56 NY2d 175, 184). More on point in this context than the doctrine of estoppel is that of waiver. A judgment which might otherwise be subject to vacatur may, in certain circumstances, not be disturbed if the proponent of such a measure has, by work or deed, waived his right to relief (Marco v Sachs, 10 NY2d 542, 550; Palisi v Yanarella, 76 NYS2d 209, affd 272 App Div 1070; cf. New York Tel. Co. v Jamestown Tel. Corp., 282 NY 365). Waiver, being a *405matter of intent (Nassau Trust Co. v Montrose Concrete Prods. Corp., supra, p 184), is generally an issue of fact to be established at a hearing or trial (422 W. 15th St. v Johnson, 258 App Div 227). Whether defendant has waived any complaint he may have on the ground of extrinsic fraud is not, on this record, something which can be resolved as a matter of law. We conclude, therefore, that a hearing should be held wherein the questions of extrinsic fraud and waiver can be explored and determined. If defendant has not waived his right to question the validity of the divorce judgment and if extrinsic fraud exists, then the judgment should be vacated, and defendant should be given the opportunity, as he requested in his motion at Special Term, to interpose an answer. In addition, the hearing should encompass the issue of whether the “stipulation of settlement” is tainted by overreaching or other improper conduct on plaintiff’s part (see Christian v Christian, 42 NY2d 63). Gibbons, Gulotta and Thompson, JJ., concur.