Saracens striving to become the Barcelona of rugby - Billy Vunipola

Saracens' trophy hunters may not have achieved greatness yet, but Billy Vunipola believes they are striving to bring Barcelona-esque levels of domination to European rugby.

The Londoners claimed their second straight Champions Cup on Saturday and will next week look to take another step towards a third Aviva Premiership crown in as many years.

Yet Vunipola still does not believe the feats performed by Mark McCall's team allow them to be included in the pantheon of sport's blue-riband line-ups.

As far as the England No. 8 is concerned, the bench mark is the achievements mustered by Lionel Messi and his Catalan counterparts on the football field.

Sarries still have work to do to reach those levels, but the 24-year-old reckons victory in next weekend's Premiership semifinal showdown with Exeter will put them another step closer.

"A great team is Barcelona, a team who wins everything," said Vunipola after his side sealed their latest triumph with a 28-17 win over Clermont Auvergne at Murrayfield. "I think we're striving towards that.

"But we will see. We have a massive game next week and if we win that it will give ourselves the chance to step up the ladder towards greatness.

"It's very early days and we still have a lot of work to do before I'd feel comfortable standing here and saying we're a great team.

"We're a young team and we have more time, but only if we stay focused and grounded. It's easy to say we're all young and a lot of success has come early, so we'll win a few more trophies.

"But you have to work for it. You have to fight for it."

The English champions were made to battle all the way to retain the European crown they won for the first time last year.

Scores from Chris Ashton and George Kruis put them in command early on but Clermont hit back.

When Nick Abendanon finished off a move that started under the Top 14 giants' own posts midway through the second half to draw them to within a point, it appeared Sarries' resolve was about to fail.

But the test of true champions is the ability to grind out results when things are not going their way, and McCall's team gritted their teeth before sealing victory with Alex Goode's late touchdown.

"It was nice because finals are always supposed to be tight," said Vunipola. "As we were walking back to halfway Faz [Owen Farrell] said to me, 'Let's fight'. I was like, 'All right, let's just do it'.

"It was good to show everybody we could get back off the canvas."