With less than 10 minutes left it looked as though this season's ASDA League Three East winners might upset the odds, bt then Tonmawr broke out of their 22 and with six minutes left on the clock Donovan skipped away for the vital winning try.
Outside half Austin Howells opened the scoring for Tonmawr with the first of their three tries; centre Ricky Price got the other one, and he also converted one try and kicked two penalties. The other Tonmawr points came from a Gareth Morris drop goal.
Penallta's points came from tries by wing Lee Thomas, hooker Dale Powell and outside half Gareth Davies. Davies, who was voted Man of the Match, converted all three and kicked a penalty.