Ponty almost slipped further behind as Keys' lock Danny Hodge intercepted and charged upfield but he failed to make the try line and the attack petered out.
The game was blighted with errors and the tension of the game saw Hodge duly dispatched to the sin bin. Dai Flanagan kicked the ensuing penalty to draw Ponty level.
Attempting to up the tempo of the game, the visitors edged into the lead when Flanagan put over another well struck penalty before Ponty finally showed some cohesion. After a sustained period of pressure, centre Gavin Dacey broke through for a try with Flanagan adding the extra two points.
With lively scrum half Gareth James to the fore, Ponty were now in the ascendancy and went into the interval holding a 10 point lead.
The second half was evenly contested but a Ponty counter-attack saw prop Chris Phillips charge over for a try which Flanagan again converted.
The home team were penalised a number of times and skipper Rob Nash was eventually shown a yellow card. Using their powerful scrum as a base, Ponty grew in confidence as the game progressed and no sooner was Rob Nash back on the field than he was brandished a straight red for foul play. Flanagan kicked the resulting penalty.
Despite Cross Keys attempting to forge their way back into contention, Ponty held out comfortably in defence and then launched a sweeping counter attack. Poaching possession in the loose, Ponty moved the ball swiftly along the back line for winger Lewis Williams to dart over for a try wide out.
In the dying minutes of the game Ponty went all out to secure a fourth bonus point try but their efforts proved in vain though their 28-3 win was no less than they deserved.