Four first half tries and two after the interval were more than enough to see off the Ospreys who were outgunned by a combative Scarlets pack.
Rhodri Williams kicked off proceedings with his side's first try of the night and by half time, Jordan Williams, Luke Harbatt and Samson Lee had weighed in with three more.
Outside half Williams, who is still an under 15, bagged 11 points in all with Curtis Morris and Gareth Thomas adding tries after the interval.
Kevin Burrows crossed in the first half for the Ospreys and Sam Davies and Ryan Evans bagged tries after the break.
Team manager Wyn Thomas said, "The boys were disappointed to go down to the Blues North last week, but I think our first game at Stradey Park lifted them.
"We dominated in the tight and when we got the ball, we looked capable of scoring. Six tries against a good Ospreys side is a pretty decebnt return for their efforts."






