The Scarlets kicked off their Pro12 campaign with a comfortable bonus-point win over last season's runners up Leinster at Parc y Scarlets.
The hosts were 14-6 ahead at the break with Scott Williams and Liam Williams going over.
Wings George North and Andy Fenby led the way in the second period.
Devin Toner went over for Leinster before Kieran Murphy, North and Fenby underlined the Scarlets' superiority ahead of Ian Madigan's late try.
Victory gave new head coach Simon Easterby a winning start at competitive level following his appointment in June.
The Welsh region had not beaten European champions Leinster in their last seven encounters in all competitions.
But while experienced flanker Shane Jennings led Leinster, their match 22 included six players from the province's Academy on the bench and they were without 11 internationals and another seven injured players.
Scarlets' had last beaten the Irish side in the opening game of the 2009-10 season.
That set the contest up for the hosts to continue a recent trend that had seen them start league seasons with victory in three of the previous four terms.
And a side including new locks George Earle and Richard Kelly was not to be denied.
Centre Scott Williams went over in the 15th minute after good approach work by the home pack.
Williams provided a fine cut-out pass for full-back namesake Liam to go over 10 minutes later.
Madigan kicked penalties at either end of the opening period, but when North went over for his side's third try soon after the restart, having initially launched the move, Leinster's hopes were fading.
When Fenby profited from a move begun by Liam Williams and continued by powerful back-rower Aaron Shingler, the outcome was certain.
Toner crossed to offer his side brief respite but the onslaught continued with Murphy's response.
North was next to cross, powering away on the right after replacement scrum-half Gareth Davies's burst.
Fenby was one of several potential try-scorers after centre Gareth Maule broke free on the left.
There was time for Madigan to add a consolation try to his two penalties and conversion of Toner's try.
But Scarlets kickers Aled Thomas and Rhys Priestland landed five conversions between them on a night that belonged to the hosts.
Scarlets: Liam Williams; George North, Gareth Maule, Scott Williams, Andy Fenby; Aled Thomas, Tavis Knoyle; Rhodri Jones, Ken Owens, Deacon Manu, George Earle, Richard Kelly, Aaron Shingler, Josh Turnbull, Rob McCusker (capt).
Replacements: Matthew Rees, Phil John, Samson Lee, Sione Timani, Kieran Murphy, Gareth Davies, Rhys Priestland, Jonathan Davies.
Leinster: Isa Nacewa; Andrew Conway, Brendan Macken, Noel Reid, Fionn Carr; Ian Madigan, Isaac Boss; Heinke van der Merwe, Richardt Strauss, Jamie Hagan, Damian Browne, Devin Toner, Dominic Ryan, Shane Jennings (capt), Leo Auva'a.
Replacements: Aaron Dundon, Jack McGrath, Martin Moore, Tom Denton, Jordi Murphy, John Cooney, Collie O'Shea, Darren Hudson.
Referee: Neil Paterson (SRU)
Assistant Referees: Tim Hayes, Martyn Lewis (both WRU)
Citing Commissioner: Geraint Edwards (WRU)
TMO: Nigel Whitehouse (WRU)