The Ulstermen's only reversal at Ravenhill in the tournament since October 2011 was 8-16 to Leinster on 20 April 2012.
Ulster have won their last six encounters with Welsh regions, whilst the Ospreys were the most recent Welsh team to win at the famous old venue, doing so on 13 April 2010.
Ospreys have now gone four successive matches without a win in all competitions; however in the RaboDirect PRO12 the Welshmen have suffered just one reversal in their last ten encounters: 13-23 at Edinburgh on 23 November. Ospreys only away win since October was 14-3 over the Dragons on New Year's Eve.
Ulster have already beaten Ospreys in Swansea in round two this year and are going for a first ever season's double over the Welsh region.
At Ravenhill , 7.05pm.
Referee: Marius Mitrea (FIR, 15th competition game) Live on
Assistant Referees: Paul Haycock, Nigel Correll (both IRFU)
Citing Commissioner: Peter Ferguson (IRFU)
TMO: Simon McDowell (IRFU)
Live on BBC NI and BBC Wales
1st Floor Simmonscourt House
Ballsbridge, Dublin 4, Ireland