The three-part challenge involves kicking to a set distance, passing the ball through a series of targets and finally a timed agility course that tests swerving and side stepping ability.
Lewis' combined score of 213.90 eclipsed second place Peter Ford of Northampton Saints by nearly 50 points.
"It was a fantastic day," said Lewis. "I really enjoyed running out on to the pitch at Twickenham in front of such a big crowd."
Simon Lane, Community Coach at Warriors, said: "The Guinness Premiership final was a fantastic occasion for the league and also the young people who had been identified through the Premier Rugby Academy camps.
"For Lewis to win his age group was a fantastic achievement and demonstrates the levels of rugby ability in West Midlands and also the impact of attending a Premier Rugby Academy camp with the Warriors."
Look out for future camps this summer by visiting the official website at www.warriors.co.uk