Treviso caused the first major shock of the RaboDirect PRO12 season as they defeated champions the Ospreys 12-6 at Stadio Comunale di Monigo.
With a day of torrential rain and the odd flash of lightning as a backdrop at the Stadio Comunale di Monigo, the home side made an industrious start to the game as the Ospreys' ill-discipline was proving to be their downfall.
With the wind at his back, Kristopher Burton kicked three penalties, one of which saw the sin-binning of Wales international lock Ian Evans sin, giving the home side a 9-0 lead.
Ospreys fly-half Dan Biggar and Burton exchanged penalties to take the score to 12-3 before Evans was shown a second yellow card and therefore sent off for a high tackle on fly-half Alberto Di Bernado.
The Welsh region's failure to control their own set-piece possession enabled the Italian side to camp in their half for much of the first period with the impressive Trevsio back-row of Simone Favaro, Alessandro Zanni, and Robert Barbieri thriving in the wet conditions.
The defending champions showed encouraging signs at the start of the second half but the Treviso pack continued their impressive dominance as their driving maul was proving to be a formidable weapon.
The only points of the second half came via a Biggar penalty in what was becoming an error-strewn encounter.
Despite playing nearly an hour with 14-men, the 4-times champions have only themselves to blame for not registering an opening RaboDirect weekend win.
Biggar missed three simple penalties, winger Tom Isaacs spilt the ball with the try-line beckoning, centre Ashley Beck was held up over the line and Treviso prop Ignacio Fernandez-Rouyet and replacement second-row Dean Budd were both sin-binned in the second half.
Pen: Burton 4
Pen: Biggar 2
Treviso: 15 Kristopher Burton, 14 Ludovico Nitoglia, 13 Tommaso Iannone, 12 Alberto Sgarbi, 11 Luke McLean, 10 Alberto Di Bernardo, 9 Edoardo Gori, 8 Robert Barbieri, 7 Alessandro Zanni, 6 Simone Favaro, 5 Corniel Van Zyl (c), 4 Francesco Minto, 3 Ignacio Fernandez-Rouyet, 2 Enrico Ceccato, 1 Alberto De Marchi.
Replacements: 16 Franco Sbaraglini, 17 Michele Rizzo, 18 Lorenzo Cittadini, 19 Dean Budd, 20 Paul Derbyshire, 21 Marco Filippucci, 22 Fabio Semenzato, 23 Brendan Williams.
Ospreys: 15 Richard Fussell, 14 Hanno Dirksen, 13 Andrew Bishop, 12 Ashley Beck, 11 Tom Isaacs, 10 Dan Biggar, 9 Kahn Fotuali'i, 8 Jonathan Thomas, 7 Sam Lewis, 6 James King, 5 Ian Evans, 4 Alun Wyn Jones (capt), 3 Aaron Jarvis, 2 Richard Hibbard, 1 Ryan Bevington.
Replacements: 16 Scott Baldwin, 17 Duncan Jones, 18 Joe Rees, 19 Joe Bearman, 20 Morgan Allen, 21 Rhys Webb, 22 Matthew Morgan, 23 Tom Grabham.
Referee: John Lacey (Ireland)
Assistant referees: Giuseppe Vivarini (Italy), Andrea Spadoni (Italy)
Television match official: Alan Falzone (Italy)