Danny grabs the lot; SWALEC CUP SIXTH ROUND.
Ellis scored all 17 points to send Caerphilly into the last eight in perfect conditions at the Riverside Park.
The first quarter saw little movement of the ball along the line as both teams probed.
On 18 minutes Rumney made the breakthrough following an excellent length-of-the-field move, second row Matthew Kelly crossed for the game's opening try.
Caerphilly's reply was swift when six minutes later outside-half Danny Ellis touched down in the corner for a try, which Rumney will know was as a result of defensive errors.
Caerphilly had the upper hand in the later stages of the first half, a brace of Ellis penalties giving the visitors an 11-5 interval lead.
The second half opened with an Ellis penalty - a sign of things to come as a further two penalties from Ellis set up a cushion for Caerphilly, despite a late surge from Rumney and a Tom Daly try.
Rumney: Try - M Kelly, T Daly; Con-DClark
Caerphilly: Try - D Ellis; Pens - Ellis (4)