Young said: "We knew it was going to be a real scrap this season with only three out of four Welsh regions qualifying for the Heineken Cup. I believed it would go down to the wire so to have it wrapped up with two games to go is fantastic."
The Blues still have a mathematical chance of qualifying for the Magners League play-offs, if they take maximum points from their remaining games and other results go their way.
Young said: "We hadn't won (at Llanelli) for eight years so to win twice this season, in the Anglo-Welsh Cup and in the league, is great.
"We played a lot more direct in the second half. A lot of things that weren't sticking and not quite going to plan started working for us.
"We have played great in the last month. The difference is we have had continuity in selection and all our internationals back."
With European qualification secured, the victory also means they can focus on their Amlin Challenge Cup semi-final clash with London Wasps.
And if they were to go on and lift the trophy, that would hand earn a fourth place in the Heineken Cup for Wales - and a route back for the Scarlets.
Young said: "It's nice the pressure is off us a little now. Obviously we will be looking to do well in the Challenge Cup for ourselves, but if we can go all the way and help the Scarlets, it would be an added bonus. It would be great to have all four Welsh regions in the Heineken Cup. I think we're all strong enough to compete."