Playing with the elements their back, Gloucester turned things around in the second half though and emerged 33-15 winners.
Lewis was pleased with how his young team responded to adversity.
"The first half was difficult as we were playing into such a strong wind. We were a bit slow getting into the game, which was different from the game against Northampton when we were straight into it.
"We've got a really good set of boys, from various age groups. We had lads from the U15s and U16s as part of that team against Worcester and they didn't look out of place,
"They went out there and showed what they can do against opponents who are much bigger and older than them, and that's really good for the future."
Northampton and Worcester have both come to Hartpury and left defeated. However, next up is a testing trip to Leicester.
Lewis knows it will be a tough test, but feels that the new league format is a positive one.
"Leicester had a good win this week, 38-0 against Newcastle, so they'll be going into the game with their confidence high. They're also getting some players back from injury. It should be a good game between two unbeaten teams.
"The new league format is really good for us, it gives us something to play for. We played mostly friendlies before. No game is ever a 'friendly' of course, but the goal of finishing top of the league gives you something to aim for."
It's the first chance that Lewis and his team mates have had to represent the Gloucester club, and he stressed that it's something that means as much to the U18s as it does to the first teamers.
"It's every bit as important to us, if not more in a way. Most of us have grown up living around here, watching and supporting Gloucester.
"We've been lucky to have Peter Buxton coaching us, and we all know who he is, we've watched him play, we've got massive respect for him.
"When it comes to game day, and you're pulling on the same shirt as someone like him, it means a lot."