THE Probert brothers shared the limelight as Berriew overcame a fourth round banana skin, in ambitious Tregaron Turfs.
Manager Russell Cadwallader praised the hosts, saying: “It was an upset waiting to happen so I am pleased to be in the next round.”
Mark Probert maintained his current purple patch, with a 20th minute header to break the deadlock for Berriew.
Younger brother Ian then cut inside from the left before lashing home as Berriew doubled their advantage.
Jon Harris headed wide and Will Thomas forced a save from goalkeeper Tom Sheehy as Berriew pushed for a decisive third.
However with seconds remaining the Turfs hit back with Darren Davies chipping Lee Andrew from 25 yards.
TREGARON: Sheehy, Weir, G Davies, C Davies, J Jones, J Evans, N Jones, G Jones, D Davies, Coleman, Abberton. Subs: Duggan, M Davies, D Davies
BERRIEW: L Andrew, Webster, M Jones, M Probert, Coulson, Davies, Pritchard, Harris, I Probert, Thomas, Ziemann. Subs; Phillips, Baldwin, Pryce