Tries by Matthew Edwards, Keith Burke, Mike Tossell and Ken Morris saw the home side totally outgunned and Gareth David added the goalkicks for the Division Two outfit, who celebrate with a home tie in Round Four against Gorseinon.
Dolgellau are the second team from the North to go through as Aberavon Quins scratched and the walkover gives a long trip to West Wales on December 27 when they will meet powerful Felinfoel.
Dunvant lost the Two west leadership by playing in the Cup and winning 19-10 at Abercarn, but Dunvant team manager Peter Thomas paid credit to the home team, stating: "They gave a tremenendous performance and tackled superbly."
Young lock Gavin Elliott made his senior debut for Dunvant and will always remember the try that was the only score of the first half.
After the interval there were further Dunvant tries by former South Gower flanker David Carey and hooker Christian Richards, both converted by wing Simon Jenkins, but the Gwent outfit responded with two tries, one of which was an interception from halfway.
Narberth were given a good contest at Cilfynydd and praised the home side's efforts to hold them to 15-5 at the interval, but the Otters ran clear with nine tries in a 55-15 scoreline.
Llanelli fly half Gareth Bowen scored two tries as a replacement with Gareth James also notching two and landing five conversions. Other tries came from Nick Jones (2), Kati Tuipulotu, David Ebsworth and Adrian Killa with flanker Gavin Jones, lock Phil Davies and replacement hooker Gwyn Way crossing for brave Cilfynydd.
Three tries by Emyr Harries helped Pontyberem to a 35-16 win at Llandybie and there were fine wins for Newcastle Emlyn over Fairwater and for Pontycymmer by 22-20 over Bryncoch.
Elsewhere, Banwen beat off Tylorstown 33-3, centenary-celebrating Amman Utd beat Tonna 22-16 and Newport Saracens gained a good 63-8 win at Betws in West Wales, but Bonymaen struggled to win at plucky Trebanos.
Konica Minolta Cup - Round 3.
Abercarn 10 Dunvant 19
Amman Utd 22 Tonna 16
Banwen 33 Tylorstown 3
Betws 8 Newport Saracens
Cilfynydd 15 Narberth 55
Dolgellau (w/over) vs Aberavon Qns (scratched)
Llandybie 16 Pontyberem 35
Newcastle Emlyn 26 Fairwater 15
Pontycymmer 22 Bryncoch 20
Trebanos 17 Bonymaen 23
Treorchy 12 Pencoed 34
Treherbert v Dowlais (playing Tuesday, December 9)
Konica Minolta Cup 2003/2004 - Round 4.
Saturday, 27th December 2003
Aberavon v Merthyr; Banwen v Pontyberem; Bedwas v Narberth; Blackwood v Senghenydd; Brecon v Llanelli; Brynithel v Bridgend; Brynmawr v Cardiff; Caerphilly v Carmarthen Ath; Corus v Nelson; Cross Keys v Carmarthen Quins;Cwmavon v Tonyrefail; Dinas Powys v Pontypridd; Ebbw Vale v Old Illtydians ;Felinfoel v Dolgellau; Llandaff North v Newbridge; Llandovery v Neath; Llangefni v Treherbert / Dowlais; Llanharan v Seven Sisters; Maesteg v Cwmllynfell; Mountain Ash v Abercynon; Nantyffyllon v Dunvant; New Tredegar v Newport Saracens; Newcastle Emlyn v UWIC; Newport v Bridgend Ath; Pontycymmer v Beddau; Pontypool v Nantymoel; Rhymney v Cwmbran; Risca v Builth Wells; Bonymaen v Amman Utd; Pencoed v Gorseinon; Whitland v Llanelli Wands; Ynysddu v Swansea.