The Ospreys and Scarlets battled to a try-less draw in the Pro-12 League at Swansea's Liberty Stadium with rival fly-halves Dan Biggar and Stephen Jones sharing the points.
Biggar kicked the first-half's only points after Jones was sin-binned for a tip-tackle on the Ospreys' Irish wing Tommy Bowe.
Home flanker Justin Tipuric was also yellow-carded for a ruck offence.
After the break Biggar kicked two penalties and Jones three.
The Ospreys reintroduced five of Wales' World Cup squad with lock Alun Wyn Jones leading them on his return and Huw Bennett, Ryan Bevington, Ryan Jones and Shane Williams coming off the bench.
Scott Williams, Jones and Tavis Knoyle started for the visitors while Ken Owens, Jonathan Davies and George North came on as the game progressed.
The opening period was typical of games between the near neighbours - tight, niggly and rarely expansive.
French referee Mathieu Raynal's task was not made any easier when veteran Scarlets fly-half Jones tip-tackled Bowe.
Instead Raynal opted for the yellow card, as many observers believe Warburton should have received - even if the Wales flanker has recently conceded Alain Rolland was correct to banish him.
It could now be left to a citing action to decide whether or not Jones should face a stiffer penalty than he suffered in Swansea.
Home 10 Biggar missed with the first chance of points, his third-minute penalty attempt drifting wide.
Jones followed suit as he was off target in the 10th minute.
But when Jones was punished for his indiscretion, Biggar fired over the game's first points.
And after openside Tipuric was sin-binned for illegally gathering the ball from a ruck with his hands, the Scarlets turned to full-back Daniel Evans to shoot for the posts.
Evans' attempt drifted narrowly wide, exacerbating fly-half Jones' absence.
The Ospreys' best chance came when new scrum-half recruit Kahn Fotuali'i launched an attack from a penalty.
But despite his best attempts at holding up the Scarlets defence, lock Ian Evans drifted into touch marginally ahead of sending the pass that Ashley Beck thought had brought a try.
So Biggar's solitary penalty was all either side had to show for their first-half efforts.
Jones levelled two minutes after the break with a mid-range penalty.
But the hosts were soon back in the lead after the Ospreys' scrum forced a penalty from their opponents, Biggar kicking the points before adding a third.
Full-back Evans failed with a second of his left-footed shots and Jones sent another penalty well wide of the uprights to put further pressure on the visitors.
Jones rediscovered his range and accuracy in the 59th minute to cut the hosts' lead to three points.
Biggar was off target in the 69th minute and Jones was over ambitious with a bid find touch close to the Ospreys' line from a penalty.
But the Scarlets had the last word as replacement George North's rare midfield charge drew the Ospreys offside, giving Jones the chance to level with less than three minutes remaining.
Ospreys: Richard Fussell; Tommy Bowe, Andrew Bishop, Ashley Beck, Eli Walker; Dan Biggar, Kahn Fotuali'i; Duncan Jones, Richard Hibbard, Cai Griffiths, Alun Wyn Jones (capt), Ian Evans, Joe Bearman, Justin Tipuric, Jonathan Thomas.
Replacements: S Williams for E Walker (55), Bevington for D Jones (53), H Bennett for Hibbard (53), A Jarvis for Griffiths (46), R Jones for A A Jones (55), G Stowers for Evans (57), T Smith for Bearman (73).
Scarlets: Daniel Evans; Liam Williams, Adam Warren, Scott Williams, Sean Lamont; Stephen Jones, Tavis Knoyle; Iestyn Thomas, Matthew Rees (capt), Rhys Thomas, Dominic Day, Damian Welch, Aaron Shingler, Rob McCusker, Ben Morgan.
Replacements: G North for L Williams (48), J Davies for Warren (48), R Williams for Knoyle (75), P John for I Thomas (59), K Owens for M Rees (59), R Jones for R Thomas (73), R Pugh for Day (69), S Timani for Welch (59).
Referee: Mathieu Raynal (France)