Billy Vunipola was like a caged tiger as he stood on the touchline with one hand pressing an ice pack on his shoulder and the other arm as high as he could reach.

The Saracens number eight had been jeered by Leinster supporters from the moment his name was read out before a brutal European Champions Cup final at St James' Park on Saturday.

It was not the first time the England powerhouse had been targeted following his support of Australia full-back Israel Folau's controversial social media posts, leading to him receiving a formal warning from the Rugby Football Union.

Vunipola had played a big part in silencing Leinster’s fans by the time he was replaced wincing late in a fierce clash of the titans in Newcastle, having scored his side’s second try in a 20-10 victory for Sarries that saw his brother Mako forced off in the first half due to injury.

Billy shrugged off four tackles to power his way over 13 minutes from time, prompting roars from the Saracens contingent and shattering Leinster’s hopes of retaining their title.

Vunipola hardly missed a tackle in the most physical of encounters, both sets of players putting their bodies on the line in pursuit of more European glory.

Saracens had played down talk of being fuelled by revenge for a Champions Cup quarter-final defeat to the Irish province last season, having won the tournament in the previous two years, but they appeared on a mission to regain their crown - driven on by outstanding captain Brad Barritt. 

Leinster scored 10 points without reply in the first half, Tadhg Furlong crashing over in the first half just after Maro Itoje was sin-binned for straying offside twice as Saracens defended for their lives.

Mako Vunipola and Titi Lamositele had succumbed to injury in a titanic tussle, so Irish eyes were smiling until George Kruis flattened Johnny Sexton - who opened the scoring with the first shot at goal - with a huge hit.

Sexton was penalised for holding on after being steamrolled by Kruis and Owen Farrell stepped up to score the resulting penalty expertly.

Farrell then produced a moment of sheer class, setting up a simple finish for Sean Maitland with a sublime pass as Jordan Larmour hurtled towards the Sarries and England fly-half.

The number 10 stepped up to nail the conversion on the stroke of half-time, so it was the Premiership champions who ran off at the break with a spring in their step.

When they resumed battle, the forwards continue to plough into each other like battering rams, but Farrell edged Mark McCall's relentless side in front for the first time from the tee.

Sean Cronin, Will Skelton and Furlong off trudged off like weary boxers before the only Vunipola still remaining on the pitch summoned up the strength to barge his way through and touch down to extend the lead, leaving Farrell with a simple conversion. 

He then wandered towards the bench nursing his left shoulder, but desperately tried to get permission from the officials to come back on with time almost up.

There was one final involvement for the forward when the ball was kicked into touch in his direction and he shrugged off the pain to celebrate a win which gave Saracens a record third Champions Cup success for a Premiership team, completing one half of a potential double in the process.