The Benetton pack did a superb job on the home side and by the end of a rugged slog in the mud it was the pride of Wales which had been severely dented.
Pontypridd have been the Cinderellas of the European Cup over the past three years and in this season, without the English clubs, they were tipped to be one of the major players at the ball.
Victories over Glasgow Caledonians and Colomiers had taken them to the top of Pool D, but this home defeat, only their second in Europe, could condemn them to the role of also-rans yet again.
By the end they were a side well beaten and lacking a certain amount of cohesion and inspiration. Their troubles lie up-front and much work needs to be done if their bid for a quarter-final place is to be successful.
As for the Italians, they were rightly jubilant at the end. Even their South African and New Zealand contingent were punching the air.
The giant presence of Springbok forwards Adriaan Richter and Wilhemus Visser made a telling impact, while the defensive skills and forceful running of Kiwi centre Cameron Rackham was another huge influence on the visiting side.
Not that the home-grown talents were far behind. The right-wing Massamilliano Perziano was the man who eventually killed off Ponty's flagging hopes with his second try midway through the second half.
The unerring boot of the outside half Francesco Mazzariol provided nine crucial points in a tense opening period. Neil Jenkins gave his side an 11th-minute lead, but Mazzariol booted the Italians ahead with two penalties and a 25-metre drop goal. He then went on to play a key role in Perziano's first try moments before the interval.
Ponty came out fired up for the second half and took only three minutes to hit back with a driving try from a line-out by the No 8 Matthew Lloyd. Jenkins converted off the touchline, added a penalty two minutes later, and suddenly it was game on.
With the deficit slashed to a single point Ponty went in for the kill. The fists started flying and the Scottish referee Ed Murray must have had feelings of another bloodbath.
The man in the middle of the infamous "Battle of Brive" last season, when Brive and Pontypridd almost fought to a standstill and were each fined pounds 20,000, lost control again momentarily.
He also found himself on the receiving end of some of the argy-bargy when the Benetton captain Alessandro Troncon pushed his hand into the face of the home hooker Andrew Lamerton, rocking his head back into the referee's face.
The official had to be patched up but was still able to see out the game. All that was left, though, was for Perziano to see off Ponty and give the Italians victory.
Pontypridd: Try Lloyd. Conversion Jenkins. Penalties Jenkins 2. Benetton Treviso: Tries Perziano 2. Penalties Mazzariol 2, Rackham. Drop Goal: Mazzariol.
Pontypridd: M Price (S Lewis, 41); G Wyatt, J Lewis, D James, G O Lewis; N Jenkins (capt), P John; A Griffiths, A Lamerton (M Thomas, 70), N Tau (M Griffiths, 71), G Prosser, A Freeman, G P Lewis, M Williams, M Lloyd.
Benetton Treviso: P Dotto; M Perziano, I Francescato, C Rackham, D Dallan; F Mazzariol, A Troncon (capt); G Grespan, A Moscardi, F Properzi, V Cristofoletto, W Visser, A Sgorlon, C Checchinato, A Richter.
Referee: E Murray (Scotland).Reuse content