George Lowe and fellow England hopeful Care also crossed for Harlequins, who failed to add a single point after the break.

Tries from Gareth Thomas, Ben Blair, Ceri Sweeney, Xavier Rush and a double from British Lion Jamie Roberts ensured the Blues' European campaign continues.

The Blues join fellow Welsh region the Scarlets in the lower-tier competition's knock-out phase while Harlequins are left to contemplate a poor showing in Europe.

Harlequins boss John Kingston: "Some of our attacking play was very good but, for whatever reason, we chose not to defend.

"If you do not front up against good teams such as Blues you will get punished, and we were.

"They were on the front foot, we were on the back foot and we did not make them work hard enough.

"This has been a hard season for a number of reasons, and we are now facing a crossroads of where we go from here in the remainder of our season.

"If we had to get turned over, this was the game for it to happen.”

Meanwhile, Sale missed out on a place in the Challenge Cup with this defeat while three-time champions Toulouse booked a home Heineken Cup quarter-final.

Needing a bonus-point victory to qualify for the second tier Challenge Cup, Sale held their illustrious opponents in a tense first half.

But Toulouse went ahead after the break through Virgil Lacombe's try.

Mathew Tait scored for Sale on 65 minutes but two Jean-Baptiste Elissalde penalties guided the French side home.