In a day to remember for Italian rugby, Aironi pulled off a massive upset to defeat Biarritz 28-27, their first victory in Heineken Cup competition.
In a game that ebbed and flowed, it appeared that a Dimitri Yachvili penalty with seven minutes to go had ensured that Biarritz would maintain their position on top of Pool Four, but the home side had other ideas.
A Julien Laharrague drop goal two minutes from time meant it was the home side who were left to celebrate a memorable victory while Imanol Harinordoquy's men where left to contemplate where it all went wrong.
Biarritz - last year's runners-up - had threatened to run away with the game in the first half before some determined work from Rowland Phillips' men helped produce a memorable comeback.
The Italian hosts were forced into some desperate early defence but couldn't stop Romain Terrain from dotting down, and the pace of Takudzwa Ngwenya bagged a second on the quarter-hour.
Two Tito Tebaldi penalties kept Aironi in touch, and James Marshall then set the place alight with a try before former England full-back Iain Balshaw restored the cushion after half-time.
Biarritz seemed to relax, allowing Nick Williams to capitalise on some committed forward graft to touch down; Tebaldi making no mistake with the conversion to edge Aironi into an 18-17 lead.
Charles Gimenez muscled over for Biarritz on the hour, but Aironi regained their lead immediately through Matteo Pratichetti's converted score.
Yachvili then looked to have broken the hosts' spirit the late penalty before the match swung again with Laharrague's dramatic 78th-minute drop-goal.
Tries: Marshall, Toniolatti
Cons: Tebaldi 2
Pens: Tebaldi 2
Tries: Terrain, Ngwenya, Balshaw, Gimenez
Cons: 2 Yachvili
Aironi: 15 Julien Laharrague, 14 Giiulio Toniolatti , 13 Rodd Penney, 12 Gilberto Pavan, 11 Matteo Pratichetti, 10 James Marshall, 9 Tito Tebaldi, 8 Nick Williams, 7 Gareth Krause, 6 Josh Sole, 5 Quintin Geldenhuys, 4 Marco Bortolami, 3 Fabio Staibano, 2 Fabio Ongaro, 1 Matias Aguero.
Replacements: 16 Luigi Ferraro, 17 Alberto de Marchi, 18 Luca Redolfini, 19 Joshua Furno, 20 Simone Favaro, 21 Pablo Canavosio, 22 Riccardo Bocchino, 23 Giulio Rubini.
Biarritz: 15 Dane Haylett-Petty, 14 Takudzwa Ngwenya, 13 Charles Gimenez, 12 Michael Bond, 11 Iain Balshaw, 10 Julien Peyrelongue, 9 Dimitri Yachvili, 8 Imanol Harinordoquy (captain), 7 Raphael Lakafia, 6 Magnus Lund, 5 Erik Lund, 4 JÃ©rÃ´me Thion. 3 Campbell Johnstone, 2 Romain Terrain, 1 Eduard Coetzee.
Replacements: 16 BenoÃ®t August, 17 Sylvain Marconnet, 18 Alexandre Barozzi, 19 Manuel Carizza, 20 BenoÃ®t Guyot, 21 Damien Traille, 22 Arnaud Mignardi, 23 Ilikena Bolakoro.
Referee: Peter Fitzgibbon (Ireland)