Cashel followed up their defeat of holders Shannon in the previous round with a 18-17 win over UCC at the Mardyke.
Clonmel, who were beaten in last season's final, had an equally fruitful trip to Rebel County – they beat Youghal 30-12.
Kilfeacle made the best of home advantage, overcoming Highfield 23-7.
The news wasn't as good for Clanwilliam and Thurles.
They lost 8-3 to Galbally and 23-17 to Young Munster respectively.
