The 23-16 triumph for Todd Blackadder's men was the centrepiece of a pulsating first weekend to the ninth season of Europe's premier club rugby competition.
We haven't cracked it yet, said Hadden. But what we have done is prove that, on a one-off given occasion, we can compete with the best while also giving ourselves a reasonable chance of qualifying for the knock-out stages.
The important thing for me is that we were dispatched pretty comprehensively by Toulouse last season - they scored 80 points in our two matches against them - but after that we sat down and said if we want to be competitive against sides like that then we had to improve.
What pleases me most is the progress made - the fact that I now like watching us play. We are playing with width and are a well balanced side.
Because if you lose your opening game at home you then have it all to do and, with just two away wins from the 12 games last weekend, that underlines how hard it is to pick up points away from home.
"Now we travel away next weekend and I was very impressed with the Ospreys the last time we met them. They took the game to us and beat us quite handsomely - we are really looking forward to Friday night.