Leinster gave Castres a 14-0 head start when the sides met at Stade Pierre-Antoine last January. Matt O'Connor's men fought back to take a 29-22 victory that day and will be aiming for a similar outcome on Sunday afternoon.
Greene King IPA Championship newcomers Doncaster Knights are the only team to boast a perfect record - 10 points from a possible 10 - after the opening two weekends of action in the British & Irish Cup.
Leinster got the job done in the second half, coming from 12 points down to defeat Wasps and go straight to the top of European Champions Cup Pool 2. Check out some photos from Sunday's game at the RDS.
Bristol set a new attendance record for a British & Irish Cup match with a crowd of 7,640 turning up at Ashton Gate last Sunday to see the Greene King IPA Championship pacesetters maintain their winning start to the season with a 50-34 victory over Connacht Eagles.
Following last weekend's interprovincial defeat to Munster, Leinster team manager Guy Easterby says he is hoping to see the 'right reaction' when the province tackle Zebre in round 6 of the GUINNESS PRO12.