It was Neath's first win in Pool win, but not even that will give their coach Lyn Jones much satisfaction as the Welsh All Blacks stand little chance of bagging a quarter-final slot with only three points from four games.
Reigning Heineken Cup champions Leicester top the Pool with seven points, their only blemish being a draw at Neath, and now they have to face an away trip to Italy and a home clash with Neath.
"You could say that today was payback time. It was an excellent performance and I'm very proud of my players, it's just a shame that we couldn't have done that last week," was Jones' matter of fact summing up of the situation after the game.
The Italians arrived cock-a-hoop after their 38-29 victory, but they departed with their tails firmly between their legs after seeing French referee Eric Darriere send three players to the sin-bin and dismissing another. At one stage in the second half they were reduced to 13 men.
They were at least competitive in the first-half, reducing an early lead of 13 points by the home side to 13-10. Tries by Kevin James and Steve Tandy, plus a penalty from Lee Jarvis, had put Neath in the driving seat before Calvisano hit back with a length of the field try by their Fijian intenational Apenisa Vodo and five points from the boot of Vincenzo Zullo.
At that stage it looked like being a close contest, but back row man Tandy's second try on the stroke of half-time gave Neath the edge once again and Calvisano's indiscipline after the break did the rest.
Msr Darriere nearly wore out his pencil as he recorded the Italian offenders. Firstly, lock Wayne Boardman departed for 10 minutes for not retreating at a penalty five minutes into the half, and then replacement scrum half Paul Griffen went for a high tackle only a minute after coming onto the field.
Skipper and hooker Giampiero De Carli, a try scoring hero on home soil a week ago, made it a hat-trick of yellow cards on the stroke of time before replacement prop Danielle Davo was given a red card for arguing with the referee.
It was a real tale of woe for Calvisano, especially as Neath made their numerical advantage pay. Msr Darriere awarded a penalty try for persistent infringements, Jarvis adding the extra points, before full back Adrian Durston danced his way through to the posts for try number five.
Jarvis had no problem in converting and Tandy soon made it a hat-trick. Jarvis again popped over the conversion and he managed to added the extra points to one more of the final three tries as Neath went for the jugular.
Hooker Steve Jones. wing James and replacement Shaun Connor rounded off proceedings with a flourish, but Neath were still left to rue their defeat in Italy.
Scorers: Neath: Tries: S Tandy 3, K James 2, A Durston, S Jones, S Connor, penalty try; Cons: L Jarvis 4; Pen: L Jarvis.