Benetton Treviso defeated Scarlets 34-28 in a thrilling contest. The Scarlets led 22-9 at the break, but the home side stormed back to register a historic win.
Wing Tommaso Benvenuti scored the winning try four minutes from the end while scrum-half Tobias Botes played a starring role.
Scarlets debutant George North, 18, touched down twice.
But North’s night and that of his team-mates came to a dire end as the hosts signalled their intentions for the season by making the visitors’ suffer.
The Scarlets rested experienced internationals Stephen Jones, Sean Lamont and new skipper Matthew Rees were rested while rising stars Ken Owens, Tavis Knoyle and Jonathan Davies were on the bench – decisions that look questionable with hindsight