Tigers ran in eight tries in the final at Newbury RFC to lift the Futures Cup.
Alex Lewington scored (2) tries and there were also scores for Rickie Aley, Gareth Clarke and Will Hurrell, while Aley kicked five conversions.
Tuilagi’s hat-trick capped a series of fine performances that saw him named man-of-the-tournament.
Tigers Academy manager Neil McCarthy said: “We are delighted to have won a national competition and produced some very good performances along the way.
“Jim Mckay did a really good job coaching the side. We were really pleased with the condition that our players were in, which is a slap on the back for Kev Mannion, the conditioning coach.”
The National Academy Sevens included sides from Sale Sharks, London Irish, London Wasps, Leeds Carnegie and Saracens as well as Newport Gwent Dragons, Ospreys, Exeter, London Welsh, Bristol and Bedford, and Berkshire, Kent, Newbury and a Barbarians seven.
England Sevens coach Ben Ryan said: “I thoroughly enjoyed the afternoon and see the quality of players on show. It is a fantastic development tool to see players express their skills and keep putting more effort in game after game.”
