CARL Evans earned Afan Lido local bragging rights and a passage into the fourth round of the Welsh Cup with a magnificent 38th-minute header from Danny Thomas's corner.
In a tight contest, it always looked as if one goal could win it and Lido are becoming masters of retaining precious leads.
The hosts attacked with wave after wave of second-half thrusts, but only Cortez Belle threatened to turn the match around with his aerial power.
But he was superbly marshalled by Evans, who is a colossus at the heart of Andy Dyer's defensive set-up.
In the first half it was Martin Rose who posed the biggest threat to Lido's supremacy, but he had a header cleared off the line and was narrowly wide with a left-foot shot.
Belle pushed forward after the interval but was constantly frustrated by poor service from the flanks as the composed Lido back line held firm without too many anxieties.
"I'm delighted as defensively we were fantastic again and we are growing in maturity, stature and confidence week by week," said Lido manager Andy Dyer.
"When I came to the club it was important we made ourselves hard to beat, but we were drawing too many times so now we are more positive going forward but still retain that steel at the back.
"Both my centre-halves were outstanding and when we take a lead we trust in other that we can see the game through.
"Port Talbot threw the kitchen sink at us in the second half.
"But we coped well and showed immense character once again.
"It's nice to get through and, hopefully, we can enjoy a home draw in the next round."