The doctrine of collateral estoppel may be invoked offensively, in support of a party's affirmative claim against his opponent, or defensively, in opposition to his opponent's affirmative claim against him. Roberto Marques, while insured by Allstate Insurance Company under an automobile insurance policy affording him up to $50,000 in underinsured motorist coverage, was struck and injured while operating his motor vehicle by a vehicle driven by Scott Oshinski. Oshinski also was insured by Allstate with a liability limit of $20,000 per occurrence. Marques filed a negligence action against Oshinski. The parties submitted to binding arbitration. The arbitrator issued an award for the plaintiff finding $20,000 constituted "fair, just and reasonable compensation" for the plaintiff's damages. Allstate paid Marques $20,000 as full compensation for all injuries and losses suffered as a result of the collision. Marques commenced this action against Allstate to recover underinsured motorist benefits under his policy alleging that his actual damages from the collision exceeded the $20,000 limit of Oshinski's coverage, which had been exhausted. The trial court rendered summary judgment to Allstate. Marques appealed contending that the court improperly found that there was no genuine issue of material fact that his claim for underinsured motorist benefits was barred by the doctrine of collateral estoppel. The Appellate Court affirmed the judgment. To recover underinsured motorist benefits under his policy, it was incumbent upon the plaintiff to prove that his total compensatory damages resulting from the collision exceeded the coverage available under Oshinski's liability policy. Because the amount of the plaintiff's total compensatory damages, as finally determined by the arbitrator, did not exceed the limit of coverage under Oshinski's liability insurance policy, Oshinski was not an underinsured operator with respect to the plaintiff's claim and, thus, the plaintiff was not entitled to recover any damages from the defendant under the underinsured motorist provisions of his policy. The defendant, the moving party seeking summary judgment, bore the burden of demonstrating that the issue raised in this action, the amount of damages to which the plaintiff was legally entitled, was litigated and determined in the plaintiff's prior arbitration with Oshinski. The defendant satisfied its burden and established the applicability of collateral estoppel and the lack of any genuine issue of material fact.