Returning Lions Tommy Bowe and Rory Best made the perfect return to Ulster colours as the hosts beat Treviso 32-13.
Sam Warburton will make his first appearance of the season for Cardiff against Leinster after recovering from injury.
Munster were knocked off the top of the table as they suffered a shock 29-19 defeat away at Benetton Treviso.
Leigh Halfpenny will make his first appearance for Cardiff this season while Munster look to make history in Italy.
Scrum-half Gareth Davies scored both Scarlets tries as the Welsh region recorded a 26-10 success over Treviso.
Week two of the Pro12 is rounded off on Saturday as Leinster host Ospreys before Treviso travel to face Scarlets.
Wales fly-half Dan Biggar kicked 14 points as the Ospreys ground out a 24-19 RaboDirect PRO12 victory over Treviso.
Exeter Chiefs will face the Heineken Cup champions for the second successive season after they were drawn with Toulon.
We preview the new season and Paul Wallace gives his verdict on the teams in the RaboDirect PRO12.
The Scarlets secured the remaining RaboDirect PRO12 play-off spot despite a 41-17 defeat to Treviso at Parc y Scarlets.
The Scarlets will look to secure their spot in the PRO12 semi-finals when they host Treviso at Parc y Scarlets.
Paul O'Donohoe's last-minute try salvaged a 23-23 draw for Connacht in Treviso.
Italy U20s back Michele Campagnaro is to make his debut for Treviso's RaboDirect PRO12 clash with Connacht on Friday.
Tries from Manoa Vosawai, Michele Rizzo and Simone Favaro led Treviso to a 30-10 win over Edinburgh at Stadio Monigo.
Edinburgh welcome the return of Scotland centre Nick De Luca against Treviso at the Stadio Monigo on Friday.
Dan Biggar scored 18 points as the Ospreys climbed back into the play-off places with a 28-3 victory over Treviso.
Ospreys name two changes to their starting line-up ahead of Saturday's RaboDirect PRO12 clash at the Liberty Stadium.
Saturday's RaboDirect PRO12 between Benetton Treviso and Connacht has been postponed due to a waterlogged pitch.
Treviso have made four changes to their line up for the visit of Connacht.
Alberto di Bernardo helped himself to 14 points as Benetton Treviso inflicted a 26-17 defeat on the Cardiff Blues.