Bath gave with one hand to Martin Johnson but may have taken with another following this emphatic, but ultimately irrelevant, victory here. Lewis Moody will be further assessed today following treatment on his twisted knee that forced him to hobble off mid-way through the second-half of this straight-forward victory.
The England captain was playing down the significance of the injury though with less than three weeks to go before he is due to lead his country into the Six Nations, Johnson could be forgiven for being anxious having already lost Courtney Lawes and Tom Croft. Moody will not travel to Biarritz next weekend for the final pool match and could be wrapped in cotton wool to ensure his role against Wales in Cardiff on 4 February.
The Bath coach Steve Meehan reported: "At this stage Lewis is very confident that it's something not particularly serious. He doesn't seem too concerned, it maybe a week out, but he seems quite confident there's nothing sinister there."
While this victory will have given rise to concern over Moody, it will have catapulted Matt Banahan into the reckoning for a starting place. The giant wing was a one-man demolition squad, scoring four tries of raw power and pace in demonstrating the qualities that only he offers England.
Never more were his abilities on show than for his first try, latching onto Shontayne Hape's delicate pass before swatting aside tackles and galloping half the length of the Recreation Ground to secure Bath's bonus point inside half an hour.
Moments earlier Banahan, having shown his athleticism with his catch from the kick off, combined with Nick Abendanon for Tom Biggs' second, either side of Luke Watson's driving score. His second, after Josh Sole hit back for an Aironi side who looked grossly out of their depth, was like a parting of the Red Sea before demonstrating his sheer will to score, stretching out through a tackle to complete his hat-trick early in the second half.
Aironi survived the loss of Marco Bortolami to the sin bin but no sooner had the former Gloucester and Italy captain returned, than Banahan showed a half-decent touch with the boot, winning the foot-race to his own kick and claim a fourth on 70 minutes.
Meehan said: "The backs fed Matt very, very well and there was a very good individual effort where he kicked ahead and chased well. If he continues to play on those lines, he's going to ask a lot of the England selectors."
Even that was not enough to deny Bath's outstanding captain Watson, who capped off the rout with his team's eighth try to be awarded man of the match. Bath still have a slim chance of progressing to the quarter-finals as one of the best runners-up, if they overturn their home defeat to Biarritz in the Basque country next weekend and other results in other pools go their way.
Bath: Tries T Biggs (2), M Banahan (4), L Watson (2); Conversions O Barkley (6); Penalties O Barkley.
Aironi: Try J Sole; Conversion J Marshall; Penalties J Marshall (3).
Bath: N Abendanon (J Cuthbert, 35); M Banahan, O Barkley, S Hape, T Biggs; B James (S Vesty, 47), M Claassens (C Cook, 71); D Barnes (D Bell, 56), P Dixon (R Batty, 52), D Wilson (A Jarvis, 62), S Hooper, J van der Giessen (I Fernadez Lobbe, 52), B Skirving, L Moody (J Ovens, 59), L Watson (capt).
Aironi: J Laharrague (R Bocchino, 59), G Pavan (G Venditti, 58), R Penney, G Pizarro, M Pratichetti, J Marshall, P Canavosio (M Wilson, 59), S Perugini (M Aguero, 49), L Ferraro (F Ongaro, 49), L Gamboa, J Furno (M Bortolami, 52), C del Fava [capt], J Sole, A Benatti (S Favaro, 54), G Krause (A de Marchi, 62). Referee: N Paterson (Scotland)