It was the Scarlets who took the upper hand during the first period as they caused the Blues defence trouble. And it was not long before the visitors registered the opening score when hooker Matthew Moore crossed the line after sustained pressure from a driving lineout.

The Blues fought back and came close to a number of scores but were frustrated with the final pass going to ground on two occasions. And it got worse before half-time when indiscretion at a ruck resulted in a yellow card for Blues flanker Leon Rogers.

The Blues started the second-half on the back foot and soon found themselves further behind when centre Keiran Jones kicked a penalty to pull the Scarlets further clear.

But a series of second-half introductions saw the Blues' replacements make a massive impact as the home side began to impose themselves on the game. With Blues outside half Calum Hall beginning to get his team playing, the Blues scored a superb try through winger Jarred Evans. Hall added the conversion and the Blues were back in the game.

And the Blues made the most of their momentum and scored a second try courtesy of flying wing Kurtis Williams to secure the win.

A late consolation try from Scarlets' replacement Harry Randall was converted by fellow substitute Joe Chiffi but it was not enough to deny the Blues their first win of the competition.