HUWS Gray Alliance leaders Caernarfon Town were stopped in their tracks as they slumped to a 3-1 home defeat at the hands of Guilsfield.
Although Danny Brockwell gave the Canaries a 32nd-minute lead, the Guils soon equalised through Jake Cook and marched on to victory with further goals from Adan Jenkins and Arron Edwards.
Caernarfon remain top as second-placed Cefn Druids were out of action, but Prestatyn Town remain third after a 2-0 home win over Holyhead Hotspur.
Goals from Jack Kenny and Joe Newell secured the points for the Seasiders in a game marred by a seven-minute touchline fracas after a tackle on Hotspur's Kenleigh Owen.
Porthmadog returned to action at The Traeth with a 2-1 home win over Gresford Athletic thanks to a 75th-minute Rob Evans winner. Earlier, Julian Williams had levelled for the hosts after Tom Wells had put the visitors in front.
Strugglers Rhayader gained three much-needed points with a 2-1 home win over Flint Town United, second-half goals from Sam Powell and Christian Jones overcoming a first-half effort from Kyle Smyth.
Llanfair United triumphed by the odd goal in five at Mold, for whom Jack Laird claimed a brace. In reply, Mark Jones and a Paul Griffiths brace sealed the win.
Buckley Town hit five without reply at home to Conwy Borough, Joe Taylor leading the way with two.