Childhood pals go head-to-head at Twickers
The two No.8s, both with a Pacific Island heritage, were first introduced to rugby in the Welsh valley town of Pontypool, famed for producing such tough Wales forwards as Terry Cobner, Bobby Windsor and Graham Price.
Faletau's father Kuli had arrived from Tonga to play club rugby for Ebbw Vale in 1997, while Billy's father, Fe'ao, came to Wales a year later and joined Pontypool.
Together with Billy's brother Mako, one of England's reserve props on Saturday, the imposing trio were all members of the same East Wales Under-11 squad.
They might have all been Wales internationals but for work taking the Vunipola family to England, where Billy won a scholarship to the prestigious Harrow school in north London.
Billy Vunipola and Faletau have been the two outstanding No.8s in Europe this season and their confrontation on Saturday, in a match that could go a long way to deciding whether current leaders England or second-placed Wales end up with the Six Nations title, has been eagerly awaited.
But Faletau has never forgotten his first rugby encounters with the Vunipolas.
"Most of the mini games we had were in Billy and Mako's back garden," the Newport Gwent Dragons loose forward said.
"Billy and my brother against me and Mako, and we would spend our time playing rugby.
"We have driven past it a few times, to see the little patch of grass we used to play on, and I can't believe half the stuff we used to do on there.
"Thinking back, I thought it was pretty big, but going back now, I realise how small it was. We tried to do anything and everything. They were good times."
Vunipola has rapidly become a cornerstone of new coach Eddie Jones's side as the Australian looks to guide England to the Six Nations title in his first season in charge.
Among the most impressed has been Faletau, who has himself completed a colossal 51 tackles this Six Nations.
"He has been outstanding," Faletau said. "He has probably been their best player, and he leads from the front.
"We will have a chat before the game, but when it comes to kick-off it's another game of rugby and he will be doing his best for his team, and I will do the same for mine.
Saracens star Vunipola is currently 3-1 up on his old pal in career meetings for club and country, although it was Faletau who came out on top when Wales beat England 28-25 in the World Cup at Twickenham in September — a defeat that played a key role in the hosts' early exit.
"We keep in contact off the pitch, but when we play against each other it's a game of rugby," Faletau said. "You don't really realise who is opposite you until after the game."
Agence France-Presse
