Cardiff beat Bridgend 23-16 at Pontypridd's Sardis Road on Sunday afternoon to advance to the final of the Konica Minolta Cup.
Victory in Pontpyridd, the home of last season's cup winners, has set up a meeting with Llandovery at the Millennium Stadium on Saturday 28 April (kick off 5.30pm).
The Drovers reached their first final with a shock 20-19 win over local rivals Llanelli at the Talbot Athletic Ground, Aberavon on Saturday.
"We have the potential for a record Premiership crowd in the final, with an east v west clash in Cardiff," said Welsh Rugby Union Group Chief Executive Roger Lewis.
Tickets are available for personal callers from the Blues Ticket Office and Shop from tomorrow or you can buy online now>>