The Anglo-Samoan juggernaut scored his second try in as many internationals as England signed off their World Cup preparations with a 20-9 victory over Ireland in Dublin.
Geordan Murphy, the Ireland full-back and Tuilagi's team-mate at Leicester, believes the 20-year-old is destined for greatness.
"Manu's going to have a massive impact at the World Cup," said Murphy.
"He'll be a force on the internationals stage for some time to come.
"He's an attacking threat and defensively his game has come on immeasurably. He's so strong. He's got to be in the England team.
"He will be a serious threat at the World Cup."
Tuilagi lined up alongside Mike Tindall at the Aviva Stadium in England's 13th different centre partnership in the 35 Tests since Martin Johnson was appointed.
The England manager has found the right solution just in time.
Tindall, panned by the critics for his performance in Cardiff a week ago, was shifted to inside centre and produced one of his most authoritative England performances for some time.
Tuilagi has been described by Johnson as a "difference-maker" and he proved it again, scorching past Keith Earls to score the opening try after five minutes.
With the England players to sit in alphabetical order on their flight to New Zealand, Tindall and Tuilagi will have 26 hours to get to know each other even better.
"It's great playing next to him. If you're in any doubt just give him the ball!" said Tindall.
"He's a physical specimen who can create anything from nothing."
Murphy knows all of the Tuilagi clan, having played with four of his older brothers - all of them Samoa internationals - at Leicester.
Manu is the youngest and he heads to the World Cup with a considerable weight of expectation on his shoulders, but Murphy believes he has the temperament to deal with the pressure.
"He's a really good guy and all the players enjoy his company," said Murphy.
"He's very grounded, I don't think that will change, and he will just get better and better.
"He's the youngest of a rugby playing family and they will all help keep his feet on the ground."
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