This win against the bottom team in Division 2 plus Penrhiwceiber losing meant that Dinas jumped up a place in the table to 14th.
The home side started well and were pressing for the first few minutes. A good cross by Reuben Bryl from the right was just too close to Chepstow's keeper Simon Martin who gathered the ball. Then Dinas centre-back Nathan Donnelly rode three tackles to eventually win an unproductive throw in.
Dinas were then caught napping and Jacques Tertas found himself one on one with James Curtin but his shot was weak and Curtin took it easily.
Bryl was having some success down the right hand side and another cross reached Myles Case but he had to hook his shot and it was just wide.
However, Dinas got the opener on 14 minutes when Adam Johns played Bryl in and he hit a superb shot just inside the right post giving Martin no chance to make the save.
The visitors raised their game winning two successive corners but the Dinas centre-back pairing of Donnelly and James Bloxham were in good form despite the fact that Chepstow are a big side with several players well over 6ft tall and the danger was cleared.
Dinas began to press again and a shot by midfielder James Marr was blocked, the ball falling to Bryl who had to hurry his shot which went wide. Chepstow were then awarded a free kick on the half-way line taken by Ian Turner but again Donnelly cleared the danger.
Myles Case then drove into the Chepstow box, squared the ball to Johns but his shot cleared the bar from 18 yards.
Chepstow had another chance from another free kick by Turner which reached Tertas but his header was well over the Dinas cross-bar.
Curtin had to rush out of his box a couple of times to clear some onrushing attacks by the Chepstow forwards. Johns then drove through on his own down the left but was chopped down just outside the Chepstow box. The free kick won Dinas a corner which Martin took and this proved to be the last action of the first half except for Tertas getting a yellow card for something said to the referee, and Dinas deserving their lead.
Both sides had half-chances early in the second half but the only shot came from Chepstow's John Watson which cleared the Dinas cross bar by a long way. Dinas could not seem to get the ball down and play to their strengths early on and the big Chepstow midfielders and strikers were winning the aerial battle. Just 10 minutes into the half Liam Head crossed to Tertas to head home the equaliser. The visitors were gaining the initiative after this and Dinas decided to ring the changes, left back Paul Caulfield was replaced by Luke Garland with 25 minutes remaining.
This had the desired affect and a minute later a through ball by Case put Johns through on goal, he drove into the box but was fouled from behind, the referee pointing straight to the penalty spot. Johns took the spot kick send Martin the wrong way to give Dinas the lead again.
Chepstow then made a substitution, Tyrone Herbert being replaced by Tom Barry.
The visitors rallied again and Curtin had to make two good saves. Dinas then made another sub, Luke Swaffield replacing the hard-working right back Sam Adamson with 17 minutes left.
Chepstow still looked dangerous at times, winning a couple of corners from the left but Dinas withstood the pressure and began to take the initiative again. A free kick by Bloxham reached Kieron James who played Bryl in but he shot straight at Martin for an easy take.
With 7 minutes to go James Perret was introduced for Case and Chepstow seemed to lose their discipline with Jago, Nathan Murphy and Watson all being shown yellow card for things said to the referee.
Despite some 8 minutes extra time being played by the referee, Dinas were well in control at this stage and deserved the 2-1 win.
Dinas squad: 1 James Curtin, 2 Sam Adamson, 3 Paul Caulfield, 4 James Bloxham, 5 Nathan Donnelly (c), 6 Nicky Bruce, 7 Reuben Bryl (1), 8 James Marr, 9 Adam Johns (1), 10 Myles Case, 11 Kieran James, 12 Luke Swaffield, 14 James Perret, 15 Luke Garland.
Pontardawe Town are the visitors to the Murch on April 30th, with a 2.30pm kick off.