Scarlets kept hold of top spot in Conference B of Pro14 thanks to a hard-fought 14-11 derby win over Cardiff Blues on Saturday.
The boot of Leigh Halfpenny proved crucial as he converted Tom Prydie and Rhys Patchell tries, helping Scarlets come from behind to seal a 10th domestic win of the season.
Wayne Pivac made eight changes to the conference-leaders' team, having criticised the artificial pitch at Arms Park in the build-up to the match, though the contest passed without any serious injury concerns.
Gareth Anscombe opened the scoring for the hosts from the tee, but Prydie crossed after brilliant work from Gareth Davies off the back of the scrum, only for Ellis Jenkins to dive over and put Blues ahead at the break.
Patchell's crucial score was not the prettiest, the former Cardiff fly-half spinning over the line as both sides made errors, but it was enough to keep his side well clear in their pool.
Ospreys remain at the bottom of Conference A, but they ended 2017 with a victory, defeating Newport Gwent Dragons 22-9 to snap a four-game losing run.
The hosts struggled to get going at a sodden Rodney Parade, only managing three Arwel Robson penalties, with Scott Baldwin, Cory Allen and Sam Davies tries ultimately enough for Ospreys.