Vunipola has rough edges to his game when his tactical awareness and fitness seem to go on the blink but he makes up for that with raw power and brutality which get England across the precious advantage line.
He had lapses at Murrayfield as everyone did in this first round but he was in the midst of most of the action and still churning through his work on both attack and defence at the end of the match. That alone will have delighted Jones.
If Vunipola can raise his fitness a tad, he has the No 8 game to challenge any in the game. He is just 23 and has played 21 tests so is only dipping his toes in the international rugby trough.
At 1.88m and 126kgs, he's got the frame to make dents in any opposition and needs to weld more experience into his repertoire. Like his coach, Vunipola was born in Australia but is being primed to be a key plank in England's recovery plans after the World Cup.
All Black No 8 Kieran Read and French No 8 Louis Picamoles led the charge of heavyweight No 8's at the World Cup while the Wallabies' David Pocock brought a different mix of vital talent to the tournament.
They were the standouts with Duane Vermeulen, Toby Faletau and Jamie Heaslip in the next rung.
Vunipola had a few injury issues and job-shared tournament work with Ben Morgan but on the evidence of today, has put a marker down in his bid to be a first choice for Jones.