Neither side had any hope of beating Pool 4 leaders Bath to qualification for the quarter-finals but Calvisano had revenge on their minds having lost the reverse fixture 36-31 back in October.

And at one stage it looked as though the Italians might see that mission through as three Paul Griffen penalties gave the visitors a narrow lead at half time, although it was Agen who crossed for the only try in the opening 40 minutes.

Former Azzurri scrum-half Griffen struck as early as the second minute and he did so again 12 minutes later to make it 6-0 to Calvisano before the quarter of an hour mark.

Agen hit back on the half hour when hooker Julien Janaudy crossed for a score that was converted by fly-half Raphael Lagarde, but Griffen’s third penalty ensured the hosts trailed at the break.

It was all Agen in the second period, though, with their second try coming just five minutes after the restart. This time it was openside Pierre Julien who did the damage, although Lagarde missed the extras to ensure the advantage was just three points at 12-9.

Both sides had players yellow carded in the 53rd minute, with right wing Belisario Agulla of Agen and Calvisano back rower Giacomo Brancoli spending 10 minutes in the bin.

And it was the home team who coped better with 14 men as they created some valuable breathing space by claiming their third try just a minute after the sin binnings. Blindside Antoine Erbani was the man to cross for the crucial score, with Lagarde’s second conversion making it a 10-point ball game.

Agen failed to push on for a bonus-point score in a disjointed final 25 minutes but they were good value for their third win of a campaign that saw them shocked by Bucharest Wolves in Round 3 but only lose to runaway winners Bath by a combined tally of eight points in rounds 2 and 5.