Rooney and Gibson touched down early in the piece to open up a 10-0 lead, with Gibson’s second coming later in the half.
Purdham and Calderwood scored soon after the break to take control of the game before Solomon Hamono grabbed Tonga’s third and final touch down.
But England had the final say with tries from Ashton and Smith to finish the game with a flourish.
Coach Paul Cullen said that his side lacked some composure, but was still pleased with the relatively comfortable win.
"It's a very exciting competition and I'm delighted to be part of it” said Cullen.
"We lacked a bit of composure not because we had players who panicked but because the Tongans hit us very hard. Every time we made a mistake they punished us.
"It was a very proud defensive effort by the Tongans. They knocked us about a bit but our guys took it and ran up a very decent score."