Legal malpractice. Plaintiff Elwell sued her attorneys for negligence in allowing the statute of limitation to run on a claim arising from a motor vehicle collision. She moved for partial summary judgment on the issue of negligence, and the attorneys as defendants also moved for summary judgment. Each motion was accompanied by an expert’s affidavit. Plaintiff appeals the denial of her motion for partial summary judgment and the grant of defendants’ motion.
The following is undisputed. The collision occurred on December 4, 1980. The attorneys were employed on July 14, 1982, and filed a complaint on behalf of plaintiff and her husband on November 29, 1982. Service was made on that defendant on April 18, 1983, and the collision case was dismissed as to plaintiff because of the statute of *424limitation. The trial court found a failure to exercise reasonable diligence in the efforts to have service perfected. This Court affirmed the dismissal in Elwell v. Haney, 169 Ga. App., 481, 482 (313 SE2d 499) (1984) holding that “the trial court did not err in its exercise of the legal discretion in finding as a matter of fact that this plaintiff wife was not diligent in her efforts to serve the defendant. . . . Clearly, there was evidence to sustain the finding of the trial court, ...”
Other significant facts are undisputed: The attorney handling the collision case did not research the law, when he filed the case four days before the statute of limitation ran as to the wife’s claim, to discover that failure to obtain prompt service as required by OCGA § 9-11-4 (c) could lead to dismissal for laches. Hilton v. Maddox &c. Trim Contractors, 125 Ga. App. 423, 425 (188 SE2d 167) (1972); Railey v. State Farm &c. Ins. Co., 129 Ga. App. 875, 880 (2) (201 SE2d 628) (1973); Webb v. Murphy, 142 Ga. App. 649, 650 (236 SE2d 840) (1977). The attorney did not advise the sheriff of the urgency of prompt service and the crucial nature of it to assure the viability of the claim. The client relied entirely on the attorney for the proper filing and service of the claim, and the attorney undertook to accomplish it. When the motion to dismiss the collision case because of laches was heard, no evidence was presented to show why the defendant was not timely served, nor was there any evidence to explain why it took four and one-half months to eventually perfect service. The attorney knew the defendant’s address when the collision suit was filed, it never changed, there was no evidence that defendant attempted to avoid service, and he was served at that address.
All of this is fact, and while it may be legally correct that the collision case is not res judicata here, the facts developed there are equally established in the record in this case and are no less true just because they were found there.
The opinion of the attorney representing the collision plaintiffs, that he pursued service “diligently and without delay” and that his conduct “fell within the parameters of acceptable professional conduct,” even without any countering expert opinion testimony, properly explicit or not, simply does not foreclose a consideration of whether what he indisputedly did and did not do constituted professional negligence. We do not agree that his opinion establishes as a matter of law that he was not negligent, when the undisputed facts are taken into account. Chief among these are that four judges concluded that plaintiffs in the collision case failed to act in a reasonable and diligent manner in attempting service, that the task of their securing service was assumed by the attorney, and that the lawsuit was dismissed for laches. These facts are more than enough to counter the defendant attorney’s opinion of his own dispatch of duty and so to create a triable issue. They speak as does the needle in the patient’s *425eye which was given in illustration of the exception to the analogous requirement for plaintiff’s medical expert opinion in Shea v. Phillips, 213 Ga. 269, 271 (2) (98 SE2d 552) (1957). The case sub judice is of the type of “unless” cases referred to in Parker v. Knight, 245 Ga. 782 (2) (267 SE2d 222) (1980). See also Killingsworth v. Poon, 167 Ga. App. 653, 655 (307 SE2d 123) (1983).
Thus, the lack of a particularized expert counter-affidavit, which appellees focus on, is beside the point. Kellos v. Sawilowsky, 172 Ga. App. 263 (322 SE2d 897) (1984), and the cases cited therein requiring expert opinion testimony, are inapposite because they do not involve dismissals of lawsuits for expiration of a statute of limitation not tolled by diligent service. As a matter of fact, Kellos states, quoting from earlier cases: “ ‘except in clear and palpable cases (such as the expiration of a statute of limitation), expert testimony is necessary to establish the parameters of acceptable professional conduct, a significant deviation from which would constitute malpractice.’ ” Kellos, supra at 264. Here we have that exceptional case.
An attorney has a duty “to use such skill, prudence, and diligence as lawyers of ordinary skill and capacity commonly possess and exercise in the performance of the tasks which they undertake.” Hughes v. Malone, 146 Ga. App 341, 344 (247 SE2d 107) (1978). See also Berman v. Rubin, 138 Ga. App. 849, 851 (227 SE2d 802) (1976). The attorney saying he did so, when the case he was handling was dismissed for laches attributable to him, does not make it so as a matter of law.
Neither plaintiff nor defendants were entitled to summary judgment, and thus the court erred as to the latter.
Judgment affirmed in part and reversed in part.
Birdsong, C. J., Carley and Pope, JJ., concur. Sognier, J., concurs in the judgment only. Deen, P. J., McMurray, P. J., Banke, P. J., and Benham, J., dissent.