Scarlets ran out 33-19 winners against the Barbarians in a memorial match for legend of both teams Phil Bennett.
The match came five weeks before Scarlets go to South Africa for their first United Rugby Championship game.
Ioan Lloyd, 22, made his Scarlets debut after joining from Bristol Bears
New signing Taine Plumtree, 23, who missed out on Wales selection for the Rugby World Cup, celebrated his debut at blind-side flanker by scoring a try for the hosts.
Veteran centre Jonathan Davies lead the hosts against a Barbarians squad who brought ex-Scarlets Rob Evans and Aaron Shingler off the bench.
The touring side had veteran Australia backs star James O'Connor at fly-half in a team including a glut of Wallabies and Japanese players who are on standby for the World Cup.
Scarlets: Johnny McNicholl; Tom Rogers, Ioan Nicholas, Jonathan Davies (capt), Ryan Conbeer; Ioan Lloyd, Kieran Hardy; Wyn Jones, Shaun Evans, Sam Wainwright, Jac Price, Morgan Jones, Taine Plumtree, Dan Davis, Ben Williams.
Replacements: Lewis Morgan, Kemsley Mathias, Steff Thomas, Harri O'Connor, Ed Scragg, Iwan Shenton, Teddy Leatherbarrow, Archie Hughes, Dan Jones, Eddie James, Tomi Lewis.
Barbarians: Ryohey Yamanaka (Japan, Kobelco Steelers); Lachie Anderson (Australia, Rebels), Filipo Daugunu (Australia, Queensland Reds), Nicholas McCurran (Toshiba Brave), Dylan Pietsch (Australia 7s, Waratahs); James O'Connor (Australia, Queensland Reds), Ryan Lonergan (capt; Australia, ACT Brumbies); Kenta Kobayashi (Japan, Suntory Sungoliath), Lachlan Lonergan (Australia, ACT Brumbies), Sam Talakai (Australia, Melborne Rebels), Josh Canham (Rebels), Uwe Helu (Japan, Kubota Spears), Lachlan Swinton (Australia, NSW Waratahs), Faulua Makisi (Japan, Kubota Spears), Harry Wilson (Australia, Queensland Reds).
Replacements: Shunta Nakamura (Suntory Sungoliath), Rob Evans (Wales, Haverfordwest), Harry Johnson-Holmes (Australia, NSW Waratahs), Cadeyrn Neville (Australia, ACT Brumbies). Aaron Shingler (Wales, Yr Hendy), Seru Uru (Queensland Reds), Kaito Shigeno (Japan, Sunwolves), James Tuttle (Melborne Rebels), Tom Wright (Australia, ACT Brumbies), Taichi Takahashi (Japan, Toyota Verblitz), Tom Lambert (Waratahs).