Unbeaten Munster maintained a perfect United Rugby Championship start with a convincing six-try win over Scarlets.

Centre Liam Coombs scored two tries with further scores from Jack O'Sullivan, Calvin Nash, Jeremy Loughman and Chris Cloete with Ben Healy kicking 13 points.

Scarlets responded with a first-half Johnny McNicholl try.

The only negative for Munster was South Africa lock RG Snyman limping off only a few minutes after coming on as a second-half replacement.

Snyman has only just returned from a long-term knee injury and this latest problem has been described as "significant".

It was a much-changed Munster side after their opening victories against Stormers and Sharks, missing established players like Conor Murray, Tadhg Beirne, Peter O'Mahony, Joey Carbery and Simon Zebo.

The alterations and absences made little impact as Munster dominated a woeful Scarlets with 21 unanswered second-half points.

Home head coach Dwayne Peel made five changes to the team that defeated Lions 36-13.

British and Irish Lions Ken Owens and Gareth Davies made their first starts of the season, while prop Wyn Jones was named on the replacements' bench, but full-back Liam Williams was missing after having his appendix removed.

On-loan Ospreys second-row Lloyd Ashley made his Scarlets debut, while Aaron Shingler was passed fit.

Fly-half Healy had fond memories of his last visit to Llanelli with a last-gasp match-winning penalty, and his 50-22 kick allowed the attacking platform for number eight O'Sullivan to power through an Owens tackle for the opening score.

Sam Costelow missed a penalty before Healy added three more points. Scarlets wing Steff Evans was denied a try after he put a knee in touch, but it would not have stood after Munster captain Jack Donoghue pointed out there had been a knock-on.

Scarlets had to be content with three Costelow points before a poor missed tackle from Evans on Nash allowed the Munster wing to sprint away and release centre Coombs to canter over for Munster's second try.

Scarlets lost Wales centre Scott Williams to an eye injury as he was replaced by another international, Jonny Williams, who featured for the first time since April after recovering from a shoulder injury.

Costelow inspired Scarlets' opening try with a clever kick that allowed full-back McNicholl to sprint onto it and score. Costelow converted and slotted over a second penalty to reduce the deficit to four points.

Munster responded emphatically with a superb Healy long pass, allowing Nash to dive over as the visitors led 22-13 at half-time.

The visitors recorded a bonus-point try from prop Loughman before Scarlets changed their front-row and lost talisman Sione Kalamafoni to injury.

Munster flanker Cloete kept stealing Scarlets' possession at the breakdown while back-row colleague Donoghue created the fifth try with a surge and chip for Coombs to expertly collect and finish.

After Snyman limped off, Cloete burst through some poor home defence for the sixth Munster try as the hosts failed to score any second-half points in a poor performance that left Parc y Scarlets stunned and subdued.

Scarlets head coach Dwayne Peel: "We are bitterly disappointed.

"We were second to everything which is the honest truth which is disappointing because it was something we worked hard on. They were very good, especially at the breakdown area, they dominated that area.

"We need to get better and there were a lot of areas we need to improve. Munster were better and hungrier in most areas, which is disappointing."

Munster head coach Johann van Graan: "We are very happy to get the win and especially the five points

"We came here with a specific job in mind and we executed our game-plan well. We scored some very good open field tries and some excellent set-piece tries.

"We coach these players every day and we've been working this project for the last five years.

"We are improving every season and it doesn't matter who takes the field, they've got a responsibility to the shirt and to come away to Parc y Scarlets and get a five-point bonus point win was excellent."

Scarlets: Johnny McNicholl; Tom Rogers, Jonathan Davies (capt), Scott Williams, Steff Evans; Sam Costelow, Gareth Davies; Rob Evans, Ken Owens, Samson Lee, Lloyd Ashley, Aaron Shingler, Blade Thomson, Dan Davis, Sione Kalamafoni.

Replacements: Ryan Elias, Wyn Jones, WillGriff John, Tom Price, Shaun Evans, Kieran Hardy, Dan Jones, Johnny Williams.

Munster: Matt Gallagher; Calvin Nash, Liam Coombes, Dan Goggin, Shane Daly; Ben Healy, Neil Cronin; Jeremy Loughman, Diarmuid Barron, Stephen Archer; Thomas Ahern, Fineen Wycherley; Jack O'Donoghue (capt), Chris Cloete, Jack O'Sullivan.

Replacements: Kevin O'Byrne, Josh Wycherley, John Ryan, RG Snyman, Alex Kendellen, Paddy Patterson, Jack Crowley, Jack Daly.

Referee: Ben Blain (SRU)

Assistant referees: Craig Evans & Simon Mills (WRU)

TMO: Neil Paterson (SRU).