Opinion by
Harlee Marshall appeals a Workmen’s Compensation Appeal Board order reversing a referee’s decision and terminating compensation. We affirm.
Marshall, a Temple. University maintenance man, received benefits after sustaining a back injury in a fall. Temple later filed a termination petition, alleging that Marshall’s disability, although continuing, was no longer related to the injury. The referee denied the petition, deciding that Temple had not met its burden of proving the claimant’s existing disability was not the result of the injury.1 The Board reversed, concluding that the referee’s decision was made in capricious disregard of competent evidence.2 Marshall appealed:3 '
Marshall argues that the Board erred in finding that the referee had capriciously disregarded .competent evidence because the evidence proffered at the hearing was conflicting. We disagree. The medical experts of both parties testified that, in their opinions, the existing disability was not the result of the in*27jury sustained in the fall, but of the natural progress of Marshall’s pre-existing degenerative joint and intervertebral disc diseases. A review of the record has disclosed no countervailing evidence.4 The Board properly concluded that the referee capriciously disregarded competent evidence because the record does not support his conclusion, but indeed supports a contrary one due to the absence of any valid basis for challenging the credibility of the expert testimony. Beth-Allen Ladder Co. v. Workmen’s Compensation Appeal Board, 53 Pa. Commonwealth Ct. 323, 417 A.2d 854 (1980).5
Marshall also argues that the Board’s refusal to grant a rehearing to allow him to introduce additional medical testimony was erroneous. This contention is without merit. The decision to grant or deny a rehearing is solely in the Board’s discretion and will only be reversed for an abuse of that discretion. Anderson v. Workmen’s Compensation Appeal Board, 51 Pa. Commonwealth Ct. 582, 414 A.2d 774 (1980). The Board did not abuse its discretion in denying a rehearing requested merely to strengthen weak proofs previously offered. Pennsylvania Glass-Sand Corp. v. Workmen’s Compensation Appeal Board, 46 Pa. Commonwealth Ct. 377, 407 A.2d 76 (1979).
Affirmed.
*28Order
The Workmen’s Compensation Appeal Board orders, Nos. A-75942 and Rehear. 3890, dated August 2, 1979 and March 12, 1980, respectively, are hereby affirmed.