SHANNON'S relegation worries intensified as they went down 10-3 to St Mary's College in the bottom-of-the-table Division 1A clash at a rain-soaked Coonagh.
Tries in either half from centre Rob Hudson and No 8 Kevin Croke helped holders St Mary's record their second win of the campaign.
Shannon, who are in the process of appointing a new head coach following the recent departure of Stephen Keogh, have yet to win a game and are now eight points adrift at the foot of the table.
Lansdowne remain on top following a decisive 36-13 bonus-point success over UL Bohemian on the back pitch at the Aviva Stadium.
After going behind early on, Lansdowne eventually took control to score five tries. Wing Cian Aherne got two of them, with the others coming from Marc Feeley, Craig Ronaldson and Sean Carey.
Lansdowne have now won five of their six games, their only defeat coming against Cork Con.
Clontarf secured a dramatic 20-18 victory over Dolphin at Musgrave Park by virtue of a penalty deep into injury-time by Darragh Fitzpatrick. Wing Michael McGrath contributed two tries, with Tim McCoy getting another.
Ballynahinch and Dublin University continue to make the running in Division 1B, both making it six wins out of six with bonus-point victories.
The northerners defeated Ballymena 43-24 away, while Dublin University hammered UCD 38-14 at College Park.
Banbridge made it five wins out of five Division 2A with a 25-12 win over Cashel that keeps them four points clear of Terenure, who beat City of Derry 38-10.
Rainey retained their unbeaten record in Division 2B by hammering Connemara 43-6.
Nenagh kept pace with a 35-20 win at Instonians.