Meanwhile, Division 2 East league leaders Rhiwbina had no trouble in winning on their short trip to Senghenydd, triumphing 33-24 in a high-scoring showdown.
Merthyr's visit to Ystrad Rhondda was expected to be the tightest tie of round three, with Ystrad Rhondda close behind joint-leaders Merthyr in Division 1 East. Ystrad had home advantage and were spurred on by their previous victory over the Ironmen at The Wern in October, where they triumphed 28-18, but Merthyr proved to be of sterner stuff this time and picked up a 23-16 victory on Ystrad soil.
North Walians Nant Conwy scraped a victory over Newcastle Emlyn, winning 18-17 on home turf and leaving the Red and Whites disappointed after their long journey. Fellow Division 1 North team Caernarfon had a comfortable home victory over Denbigh at 25-0.
Waunarlwydd secured their place in the next round after winning 11-9 against hosts Cwmllynfell, while Nelson also triumphed over guests Rumney, 6-3. It was a welcome victory but the result pales in comparison with their 23-16 triumph over the same side earlier in the season.
Elsewhere, Division 1 West's Kidwelly saw off league neighbours Whitland with an impressive 14-0 win, while Maesteg Quins of Division 2 West triumphed over last season's beaten quarter-finalists Llantrisant, winning comfortably 16-0.