Munster and Leinster now top their respective groups following victories on the road over Rotherham Titans and Jersey, while Ulster remain in second behind Bedford.
The only downside was Connacht Eagles loss to Cross Keys, the Welsh side winning 17-12 at home.
Reigning champions Munster had a particularly significant victory over the Titans, who were regarded as odds-on favourites based on previous results.
However, a new-look Munster produced the goods to win 36-21 and earn a bonus point which makes them firm favourites to advance to the quarter-finals. The return fixture is in Musgrave Park on Friday night and victory there might be enough to propel them into the knockout stages.
Munster had a penalty try and further scores from Luke O’Dea, James Cronin, Sean Henry and Scott Deasy, with Deasy banking four conversions and a penalty.
Leinster had to fight a lot harder to get the better of Jersey but produced a fine second-half. Leo Auva’a and Rhys Ruddock scored tries while Noel Reid kicked two penalties.
For Ulster, two tries from Chris Cochrane, one apiece from Adam D’Arcy and Ali Birch, a penalty try and 15 points from Stuart Olding’s boot put paid to a spirited Cardiff side, 40-14, and they collected a bonus point for good measure.
MUNSTER: D Hurley; L O’Dea, D Barnes, I Dineen, J Murphy; JJ Hanrahan, C Sheridan; J Cronin, S Henry (capt), J Ryan; D Foley, I Nagle; B Hayes, R Murphy, S Buckley. Replacements: D Casey, C Condon, P Donnellan, J O’Donoghue, B Slater, S Deasy, R O’Mahony.
LEINSTER: C Marsh; A Boyle, B Macken, J Coghlan, A Byrne; N Reid, J Cooney; J O’Connell, A Dundon, J Hagan, B Marshall, T Denton, R Ruddock (captain) D Ryan, L Auva’a. Replacements: T Sexton, M Moore, T Beirne, C Gilsenan, L McGrath, T Daly, S Crosbie.
ULSTER RAVENS: A D’Arcy; R Andrew, M Allen, N O’Connor, C Cochrane; S Olding, M Heaney: C Carey, N Annett, R Lutton, J Simpson, N McComb (capt), C Joyce, A Birch, M McComish. Replacements: R Herring, A Macklin, A O’Connor, S O’Connell, B McIlroy, S McCloskey, R Scholes.
CONNACHT A: J Loxton, M McCrea, T Leader, B Murphy, M Healy, J Carty, D Moore; R Sweeney, K O’Byrne, P Reilly, J Gardiner, D Gannon, D Heffernan, E Grace (capt), A Conneely. Replacements: K Haupt, P Griffin, C Kindregan, TJ Anderson, M Walsh, F Gormley, S Toal-Lennon.