An exhibition of blistering pace from the 20-year-old Leicester wing, who had never played in a sevens tournament before, saw him score 10 tries in the competition, including a brace in the final.
He was also the semi-final hero, scoring to seal a nailbiting 7-5 win over Samoa, after helping himself to another double in the quarter-final win over Argentina.
New Zealand coach Gordon Tietjens led the plaudits by describing Varndell as "the fastest thing I've seen on a rugby field," although England coach Mike Friday believes there is still room for improvement.
"Tommy V was sensational, that is true. But he is a young player and he has a few things still to learn. That is why he is on the sevens circuit, to ensure that he develops his game," Friday said.
"He has had a wonderful tournament but he will need to keep his feet on the ground."
Varndell himself was humble in his assessment, and insists there is no way his success will go to his head.
"I know if you let your feet get off the ground, there are plenty of guys who will knock you back to the floor if they get the chance," said Varndell.
"I just want to take it tournament by tournament and then go back to Leicester and do what I can for my club."
England had qualified for Friday's knockout stages after beating Kenya 52-7, Uganda 48-0 and Australia 33-5 in Pool C on Thursday.
However, they were made to work hard in a thrilling final.
Fiji started brilliantly, with Jone Daunivucu beating four players to score a superb try, giving the world champions the perfect start.
But England's speedster Varndell used his pace to race past two players and score under the posts.
The islanders responded, though, and they first drew players right, then sent the ball left and exploited a perfect overlap to send Epeli Dranivasa over to restore their lead.
A refereeing error, after England were let-off following an apparent knock-on, allowed Ben Gollings to power over the line, and the same player converted to give his side a 14-12 lead at half-time.
Shortly after the interval Luke Narraway pierced the defence and offloaded perfectly to Gollings, who went inside to extend the lead.
Daunivucu then showed why he was close to taking Varndell's award as Player of the Tournament as he beat four players before popping the ball up for Sireli Naqelevuki to bring the contest back to within two points.
However, Varndell finished it off with a try from short range in the corner to secure England's victory, even though William Ryder grabbed a late try in the dying seconds for Fiji.
Elsewhere, New Zealand won the Plate final, beating France 19-7, while Wales took the Bowl with a 19-5 win over Canada and Kenya took the Shield by beating Tunisia 10-7.