The Ospreys overpowered the Scarlets 36-14 to set up an EPCR Challenge Cup quarter-final.
Ospreys wasted no time to get their noses in front in the Welsh derby, Adam Beard crossing on minute one for the lead.
Captain Jac Morgan then led by example to double the hosts’ advantage before five minutes had passed.
But the experienced Blair Murray clawed the visitors back into it on 10 minutes.
But the Scarlets’ afternoon didn’t improve as they would’ve hoped. Rhys Davis and Dewi Lake each scored to give the hosts an almost 20-point lead before the break.
Any Scarlets hopes to come out for the second-half on the front foot were soon extinguished by an inspired Ospreys side. Jack Walsh went over 12 minutes after the restart before Daniel Kasende joined the festivities nine minutes later.
Eddie James got one back for the visitors inside the final 10 minutes, but it was too little, too late for Scarlets.
The Ospreys claim Welsh bragging rights and set themselves up for an EPCR Challenge Cup quarter-final against either Lyon Olympique Universitaire.
Scorers:
Ospreys: Tries: Adam Beard, Jac Morgan, Rhys Davies, Dewi Lake, Jack Walsh, Daniel Kasende. Conversions: Dan Edwards (3).
Scarlets: Tries: Blair Murray, Eddie James. Conversions: Ioan Lloyd (2).
Teams
Ospreys: 15 Jack Walsh, 14 Daniel Kasende, 13 Evardi Boshoff, 12 Keiran Williams, 11 Keelan Giles, 10 Dan Edwards, 9 Reuben Morgan-Williams, 8 Morgan Morris, 7 Justin Tipuric, 6 Jac Morgan (c), 5 Adam Beard, 4 Rhys Davies, 3 Tom Botha, 2 Dewi Lake, 1 Gareth Thomas. Replacements: 16 Sam Parry, 17 Garyn Phillips, 18 Ben Warren, 19 James Fender, 20 Morgan Morse, 21 Luke Davies, 22 Owen Williams, 23 Iestyn Hopkins.
Scarlets: 15 Ioan Lloyd, 14 Ellis Mee, 13 Macs Page, 12 Eddie James, 11 Blair Murray, 10 Sam Costelow, 9 Archie Hughes, 8 Vaea Fifita, 7 Josh Macleod (c), 6 Taine Plumtree, 5 Max Douglas, 4 Alex Craig, 3 Henry Thomas, 2 Marnus van der Merwe, 1 Kemsley Mathias. Replacements: 16 Shaun Evans, 17 Alec Hepburn, 18 Gabe Hawley, 19 Sam Lousi, 20 Jarrod Taylor, 21 Gareth Davies, 22 Joe Roberts, 23 Ioan Nicholas.