It was bittersweet emotions for Paul Marshall and Ulster after their opening day draw against Scarlets and the scrum-half insists they will need a complete performance against Zebre. The Irish province opened up their GUINNESS PRO12 campaign with a dramatic 32-32 draw in Wales and now welcome the Italians to the Kingspan Stadium for their home opener. Marshall and co ran in four tries in all in Wales but still couldn’t emerge with the victory as they shipped four tries as well. And the three-times capped Ireland international has called for an improved showing in defence against Zebre on Friday. “From our point of view we don't want to concede anywhere near that many points again this weekend,” said Marshall. “Hopefully some of the good attacking we had last weekend will stand to us and see us try and kick on again with that this week. “If we can score four tries again we shouldn't be drawing those games but winning them. “Hopefully now we can put in a performance on Friday that will justify our facilities and justify our fan base as well. “After those couple of close runs last year, Zebre will be looking to take our scalp. But we know we're a good side and we know we have to perform under pressure to get the rewards. "Hopefully we are going to be a force to be reckoned with." British & Irish Lion Rory Best is one of eight changes to the side that drew in Wales, the hooker is joined in the front row by Andrew Warwick, with Wiehahn Herbst retaining his place at tighthead prop. Dan Tuohy also keeps his place and is partnered at lock by Lewis Stevenson. Nick Williams comes into the side at No.8 and is joined by Robbie Diack and Chris Henry who gave impressive displays at Parc y Scarlets. Darren Cave makes his first start of the season and with Luke Marshall forms an experienced midfield partnership. Andrew Trimble and full-back Ricky Andrew come into the back three alongside Craig Gilroy. Paul Marshall and Ian Humphreys will combine at half-back once more. Ulster's only victory in their last five GUINNESS PRO12 encounters was 19-17 at Munster in round 22 last season. They were defeated 22-20 on their most recent match in Belfast and have not lost back-to-back matches at the Kingspan Stadium since April 2010. The Ulstermen's only previous defeat to an Italian opponent in any tournament came at home to Treviso in the GUINNESS PRO12 in October 2011. Zebre meanwhile have slipped to successive defeats, at Glasgow and at home to Cardiff Blues, while their only previous away victory came at Cardiff in round 3 last season. Ulster have won all four previous contests against Zebre although the Italians have garnered two losing bonus points and a try bonus point along the way. At Kingspan Stadium, 7.35PM Live on BBC Northern Ireland Referee: Leighton Hodges (WRU, 42nd competition game) Assistant Referees: Peter Fitzgibbon, John Carvill (both IRFU) Citing Commissioner: Eugene Ryan (IRFU) TMO: Marshall Kilgore (IRFU)