Penarth are out of the WRU Division One Cup following a 16-13 defeat at Aberavon Green Stars in the quarter finals.
The Bears were ahead by just one point at the break amid tough muddy conditions at the Pavilion Ground in Port Talbot on Saturday
Harry Williams and Osian Coates crossed for the visitors with Rhys Mottram adding a penalty but missing both conversions as the hosts edged past to book their place in the semis.
Penarth remain top of Division One East Central - and resume their Admiral League title campaign next Saturday when they entertain struggling Cambrian Welfare at the Athletic Ground.
Elsewhere, the Division Two Cup quarter final between Cowbridge and Clwb Rygbi Cymry Caerdydd was postponed due to a waterlogged pitch.

A number of changes are coming to Cardiff's International Sports Vilage
Barry RFC Proposes New Walking Route Across Reservoir Fields Following Community Feedback
Barry Bowlers head on tour to Kenya
Dinas Powys run in 21 unanswered points in second half against Gilfach Goch
Barry Youth overcome slow start to beat Beddau in Cardiff Division 2
Barry Rugby Football Club has lodged plans for extensions to its clubhouse and other works
Missed chance proved Barry's downfall against Caerphilly
Barry RFC Youth lose to Llandaff in Cardiff Rugby 2 League
Barry RFC girls coach recognised by Cardiff Rugby Community Foundation
Barry Town United end 26-year wait to lift Nathaniel MG Cup
Welsh legend Max Boyce and record-breaking footballer Jess Fishlock honoured at St David Awards