Pennock sets it up for side.
Caersws squandered home advantage in the Loosemores Challenge Cup semi-final first leg and lowly Carmarthen now have an unexpected opportunity to finish their desperate season on a high.
But the visitors have goalkeeper Tony Pennock to thank for their unlikely second-leg bonus. The Welsh semi-professional international was on the top of his game.
He brilliantly denied Graham Evans in the opening minute and further great saves to thwart Chris Venables and Mark Howells were out of the top bracket.
Caersws, who had thrashed Carmarthen 7-1 on an early-season visit to the Recreation Ground, dominated possession but were guilty of some very lax finishing.
Luke Fayers and Dale Price both went close for Carmarthen, who will now assume the mantle of favourites when the sides meet again in the second leg on March 6.