Having leaped to a 26-0 lead after just 20 minutes, Old Boys appeared on track for yet another one-sided win, but Valley dominated much of the rest of the game in miserable conditions.
Maheno played smarter rugby in the conditions to beat Athletic Marist 26-21, and Kurow pipped Excelsior 20-16 as the weather proved a leveller for all teams.
The North Otago women's team beat Alhambra-Union 39-27.