Johnny McNicholl's late try saw Scarlets claim derby victory over Ospreys in the United Rugby Championship.

That allowed Scarlets, playing their first meaningful game since October, to come out on top in a scrappy affair.

Scarlets move up to ninth in the table, while Ospreys remain fourth.

In a game played behind closed doors because of Welsh government Covid-19 regulations, Scarlets started well and enjoyed success with the season's new 50:22 rugby law, which gave them a good attacking platform.

Fly-half Dan Jones also showed intent by turning down relatively easy attempts at the posts, but perhaps in part to their lengthy Covid-related lay-off, Scarlets' lineout malfunctioned.

They earned their first try through a sustained period of pressure in open play, with scrum-half Gareth Davies benefiting from some good work by the pack.

But Scarlets were dealt a blow as Josh Macleod's miserable run of luck continued. The flanker hobbled off with a hamstring problem just 10 minutes into his long-awaited return after an Achilles injury.

Momentum then shifted to the away side, with Owen Watkin leading Ospreys' charge into Scarlets territory.

Like their hosts, Ospreys turned down kickable penalties in hunt of the try-line. They crossed from a five-metre lineout, but could not get the ball to ground.

Pressure was eventually converted as Webb crossed from close range with a cheeky show and go.

But the scrum-half did not celebrate as he instead made an allegation of eye-gouging. After consultation with the TMO, the referee said there was no clear evidence of foul play.

Ospreys looked to have crossed for a second try just before the half-hour mark, Watkin again with the break as the ball was shipped out wide for Dan Evans to cross in the corner, but excellent defence by Tom Price saw the ball held up.

Ospreys did get their second on a counter-attack. A poor cross-field kick from Jones landed in the arms of Luke Morgan who belted the ball up pitch to set up a 50-metre sprint chase with McNicholl, and it was Ospreys' former sevens star who won the race.

Scarlets looked to hit straight back only for Blade Thompson to be hacked down two metres short. The miracle offload did not come off as Rob Evans knocked on and the chance went begging.

They did finish the half with a flourish with some big drives from Thompson and Sione Kalamafoni, but the Ospreys defence was up to the task as they took a five-point half-time lead.

Scarlets began the second half well and a change of tactics saw Jones opt for the posts when a penalty was on offer, but he pulled the effort wide.

The curse of the tee would be passed on to replacement fly-half Rhys Patchell, who would surely have been given a rapturous welcome had home fans been present as he made his first competitive appearance since October 2020.

His impact was almost instant, as he produced a lovely ball which released the backs to find Steff Evans in acres of space on the left wing. He crossed to bring the scores level, though the conversion hit the woodwork.

Scarlets fumbled the subsequent kick-off and a quick tap penalty from Webb saw former Scarlet Jac Morgan make good ground. Webb once again darted over from close range with young fly-half Josh Thomas adding the extras from the touchline.

Momentum shifted once more as Scarlets' offload game finally started to click. A poor pass by Thomas, who had otherwise impressed, was intercepted for Sam Lousi to release McNicholl down the wing to race in for his first try.

Patchell shook his head as he once again missed a conversion which would have brought the scores level, and his luck was no better when he attempted a touchline penalty five minutes from time.

But Scarlets continued to push and were rewarded at the death as McNicholl came off his wing to cross for a bonus-point try after Ospreys ran out of defenders.

Scarlets head coach Dwayne Peel told BBC Sport Wales: Obviously very happy with the win, it could have gone either way to be fair.

"I was really happy with the second-half performance because the first half we were in and out of the game, we showed some good stuff but were error-ridden as well.

"Physically I'm really happy because you don't know how you're going to fare. There's a long way to go but games will give us fitness."

Ospreys head coach Toby Booth told BBC Sport Wales: "Brutally disappointing, we had enough opportunities to win it twice over.

"We've been over the line two, three times and you've got to convert and we didn't and that's really, really disappointing, especially given the nature of the festive, New Year derby against your closest rivals.

"It stings a lot for sure."

Scarlets: L Williams; McNicholl, S Hughes, S Williams (capt), S Evans; D Jones, G Davies; R Evans, Elias, O'Connor, Lousi, T Price, Thomson, Macleod, Kalamafoni.

Replacements: D Hughes, S Thomas, W GriffJohn, Shingler, Lezana, Hardy, Patchell, T Rogers.

Ospreys: D Evans; Giles, Collins, Watkin, L Morgan; J Thomas, Webb (capt); N Smith, Taione, Francis, Griffiths, Beard, Roots, J Morgan, M Morris.

Replacements: Lake, G Thomas, Botha, Ashley, Cross, Aubrey, Hawkins, K Williams.

Referee: Adam Jones (WRU)

Assistant Referees: Ben Breakspear (WRU), Rhys Jones (WRU)

TMO: Sean Brickell (WRU).