St Mary's got their league season off to the ideal start after beating champions Shannon 26-21 at Templeville Road this afternoon.
Blackrock cruised to a 26-12 win over Dungannon at Stradbrook while Clontarf went down 21-15 to Ballymena at Eaton Park.
Buccaneers also made an encouraging start with a 19-9 defeat of Garryowen. Elsewhere Cork Constitution beat Galwegians 14-8.
AIB League - Division One
Ballymena
21-15Clontarf
Co. Carlow
24-6Terenure College
Blackrock College
26-12Dungannon
Galwegians
8-14Cork Constitution
Garryowen
9-19Buccaneers
St. Mary's College
26-21Shannon
U.C.D.
20-29Lansdowne
U.L.Bohemians
6-8Belfast Harlequins
AIB League - Division Two
Ballynahinch
25-19Thomond
Bective Rangers
43-7Portadown
Dolphin
32-3D.L.S.P.
Malone
P-PU.C.C.
Midleton
18-6Greystones
Old Belvedere
33-28Sunday's Well
Old Crescent
34-11Dublin University
Young Munster
17-10Barnhall
AIB League - Division Three
Ballina
21-12City of Derry
Banbridge
29-30Waterpark
Suttonians
6-15Instonians
Naas
33-9Skerries
Highfield
22-14Queens University
Monkstown
3-11Corinthians
Wanderers
18-19Old Wesley
Clonakilty
17-12Connemara