Mary's attack will need to improve in Clontarf battle
(all Saturday 2.30, unless stated)
Clontarf v St Mary's College, Castle Avenue, (Tonight 7.30).
Third-placed 'Tarf are hot in pursuit of UCD and Cork Con and have shown improvement to beat Garryowen at home and Dolphin away.
St Mary's just about got over the line against Ballynahinch for their first win. They will have to improve their attack.
Ballynahinch v Lansdowne, Ballymacarn Park
Leinster lock Tadhg Beirne is unlikely to return from injury, leaving coach Mike Ruddock likely to go with the same team again.
UCD v Dolphin, Belfield.
Captain Shane Grannell is back from injury for the League leaders as they bid to make it four out of four.
Young Munster v Old Belvedere, Tom Clifford Park.
Wing Josh Glynn must prove his fitness to coach Paul Cunningham and Belvo want to see more of Leinster Academy prospect Jack Conan.
Belfast Harlequins v Blackrock College, Deramore Park.
Rock coach Ben Manion delayed his selection due to a number of fitness tests on the way to a club which is winless after three rounds.
Terenure College v Malone, Lakeland's Park.
Nure are absolutely flying with a 100pc record, and former Ireland Clubs international lock Fergal Walsh is making a big impression.
UL Bohemian v Dublin University, Annacotty.
Nick McNamara is likely to make his first start for Trinity in place of number eight Jack Dilger, out with a rib injury.
Naas v Seapoint, Forenaughts.
Player/coach Niall Carson has opted for the same starting XV for the third week in a row.
There is a re-jigging of the Seapoint back row with Dylan Greene coming in at blindside and Stephen Verso moving to number eight.
Ballymena v Old Wesley, Eaton Park.
Out-half Alan Large broke his leg in training last Thursday and is out until the New Year. Rory Stynes will steer the ship in his absence.
Bective Rangers v City of Derry, Donnybrook.
Rangers will be out to set straight their poor record against Derry, having lost to them in the last two seasons.
NUIM Barnhall v Old Crescent, Parsonstown.
Props Ben Harrison and Lee Mitchell will get their chance in the front row and Conor Feeney comes in on the openside.
Skerries v Boyne, Holmpatrick, (Tonight 7.30).
The North Dublin club look to make it four wins on the spin under the lights in what is a shootout between two unbeaten clubs.
Tullamore v Nenagh Ormond, Spollanstown, (Tonight 8.0).
Flanker Kevin Browne comes into the back row with Gavin Kelly switching to number eight.
Suttonians v Navan, McDowell Grounds.
Coach Noel Hehir will take the same side into the trenches against the Meath club.
DLSP v Midleton, Kirwan Park.
Salmo's Phil de Barra is out and Kimi Matangi is struggling with injury .
Instonians v Greystones, Shaws Bridge.
Captain Ben Armstrong will be all the better for last week's run-out after an injury as Stones challenge at the top end.
– COMPILED BY DES BERRY