The Sardis Road club had gone into the game knowing a solitary point would have been enough to secure first place and they secured that and more in an impressive display.
Scott Roberts opened the scoring for the visitors and there four further tries as Dale McIntosh's side ran out 7-35 winners.
Adam Thomas followed Roberts by crossing in the first half but Cardiff responded with a try from Wales Sevens centre Cory Allen as Pontypridd led 14-7 at the break.
Simon Humberstone and James Thomas had kicked the rest of the points but three second half scores through a second from Thomas, Gary Williams and Owen Jenkins secured the win.
Pontypridd had shown their intent early on by kicking a penalty to touch and their adventure was rewarded when scrum half Lloyd Williams found prop Roberts in support to cross for the opening score. Humberstone converted for a 7-0 lead.
The visitors were already hitting top gear and a second try soon arrived, Williams storming through the opposition defence and feeding full back Thomas to cross for a try which Humberstone again converted.
It was all Pontypridd but after seeing a third score disallowed for a knock on, they were served a reminder when Allen stretched over the line to score. Thomas' close range conversion improved the score as Cardiff trailed by seven going into the second half.
Allen's score seemed to merely inspire Pontypridd further and in the second half, wave after wave of attack secured the win.
Thomas soon added his second try, again converted by Humberstone and although a number of substitutions interrupted the flow of the game, the visitors were firmly on top.
And when Dai Flanagan, who had replaced Humberstone, kicked through, Williams grounded for his side's fourth score.
Winger Owen Jenkins then raced clear for the final score, Flanagan converting both tries to secure top spot.
The leaders now turn their attentions to this weekend's SWALEC Cup semi-final with Carmarthen Quins.