Pro12: Scarlets can stun Ulster, says flanker Josh Turnbull Flanker Josh Turnbull says the Scarlets can upset the Pro12 play-off semi-final odds against Ulster on Friday by following Treviso's example. The Italian side posted a 17-41 win at Parc y Scarlets last Friday. But Turnbull says his side should take confidence from making the last four, adding: "Treviso came over here on Friday and had nothing to lose and threw it around. Possibly we've got to have the same sort of game as that. Five-times Wales capped Turnbull, 25, also points to the Scarlets boasting a Pro12 double over Munster this season as proof of their credentials. Scarlets and Wales wing George North discusses the Pro 12 semi final and his impending move to Northampton Saints. We've gone to Munster this year and done the double over them. We've beaten some tough teams at home and away and we know we're capable of doing it. [But] we've got to bring our A game. Even so the versatile back-five forward, who plays open-side at Ravenhill alongside fellow Wales internationals Aaron Shingler and skipper Rob McCusker in the back-row, admits the Scarlets were a "little bit lucky" to reach the play-offs. On the night they lost to Treviso, Welsh rivals the Ospreys' hopes of successfully defending their crown ended at Leinster. "We're a little bit lucky, really, especially knowing that the Ospreys are capable of going out to Leinster and getting a W after they won out there in the final last year," said Turnbull. We're pretty relieved that we've ended up getting in the play-off. But I think we've been close in the last couple of years and we wanted to finish off this season with a bang. Turnbull says the Scarlets must contain Ulster scrum-half Ruan Pienaar and outstanding number eight Nick Williams. He added: "If we can close those two players down, it'll make our life a little bit easier. They've got a really good set-piece and to be fair they've played some pretty exciting rugby. It's a great place to play, but we've got to go out there full of confidence that we've earned the right to be in the top four this season. But while the Scarlets head to Belfast in the knowledge that they lost heavily there in January, Turnbull said other teams have mounted serious challenges to Friday's hosts. "They gave us a bit of a thumping [but] if you look at some of the results they've had against other teams, they haven't beaten them by a lot of points," he added. And Treviso even had a draw against them and they thumped us last weekend. Watch Ulster v Scarlets live on S4C on Friday from 19:30 BST. There is also live commentary on BBC Radio Wales & online and Radio Cymru.