Eldoraigne ground out a 10-5 win over Hudson Park, while Noordheuwel, Ben Vorster, Waterkloof, KES and Rondebosch also claimed wins on day one of the KES Easter Festival.
Hudson Park started brightly against Eldoraigne, but in the end their failure to convert scoring opportunities into points proved costly.
They scored the opening try for a slender 5-0 lead at half-time, but fell off the pace after the interval.
Eldoraigne grew in confidence in the second half and scored 10 unanswered points – a converted try and a penalty – to stun Hudson Park, who are one of the best teams in the Eastern Cape.
In other matches on day one, Noordheuwel snuck past Northwood 19-13, Ben Vorster defeated Kingswood 25-10, Marlow suffered a 25-12 defeat against Waterkloof, KES stunned Wynberg 42-17 and Rondebosch eased past Jeppe 26-0.