Dragons regain lead with Rodrigo Martinez try and de Beer conversion early in second half
Sam O'Connor try and Costelow extras put Scarlets back ahead
Huw Anderson bags a bonus-point try for Dragons as Dee gets his second to extend Dragons' lead, with de Beer adding conversion
Ioan Jones scores bonus-point try for Scarlets to set-up tense finale, but last-gasp Rob Hunt try seals victory for hosts, with Jac Lloyd converting
Erich Cronje, PJ Botha, Morne Brandon, Boeta Chamberlain and Kelly Mpeku (2) tries along with five points from Chris Smith earn Lions comfortable bonus-point win over Ospreys earlier on Saturday afternoon
Kieran Williams and Efan Daniel tries - along with Dan Edwards conversion - put visitors ahead at half time - with Ross Moriarty adding late consolation try
Live Reporting
Fraser Watson and Chris Kirwan
'Brilliant' first halfpublished at 15:50 BST 3 October
15:50 BST 3 October
HT: Dragons 12-14 Scarlets
Gareth Delve Former Wales international on BBC Radio Wales
It's been a brilliant first half.
We've seen such a variety to the Dragons attack, and they're so willing to taking chances instead of taking points.
Dragons win a very kickable penalty in the middle of the pitch but continue to back their driving line-out.
De Beer bangs the ball into the 22, although it's not the most ambitious of kicks. Angus O'Brien, who is close to a return from a leg injury, would normally be carrying out that duty.
Dragons looks to get their maul going but knock on at the line-out.
The hosts have a poor conversion rate in the 22 so far.
Converted try: Dragons 12-14 Scarletspublished at 27 mins
27 mins
Macs Page (con: Sam Costelow)
Image source, Huw Evans Picture Agency
Eddie James carries hard and then Scarlets work a clear opening.
Sam Costelow seems to take the tougher option of a long pass to Page on the wing - Ellis Mee looked to have a run-in from a pop pass - but the fly-half nails it to give the wing a simple finish.
Costelow then bangs over the conversion to put the visitors in front.
Scarlets are sharp but Dragons are winning collisions.
They press again in the 22 but the last pass isn't quite sticking. This time it's Rio Dyer that loses possession after gathering Tinus de Beer's cross-kick.
Rhodri Williams snipes in the 22 but Scarlets scramble. They knock the ball on so Dragons will get another chance from a scrum around 15 metres out in a central position.
Tinus de Beer was absolutely flattened by Sam Lousi and will need treatment.