With Terenure College slipping up, Lansdowne are the new leaders of Division 1A after coming from behind to beat St. Mary’s College 16-10 on the Aviva Stadium’s back pitch.
Mike Ruddock's charges, who trailed 10-3 at half-time, knuckled down in the second half as tries from replacement prop Peter Dooley and winger John Coleman saw them claim their fifth league triumph on the trot.
Lansdowne's latest win owed much to a five-minute defensive masterclass right at the death which saw them emerge as six-point victors, sealing top spot for the Christmas period.
It was a bitterly disappointing outcome for St. Mary's who will feel they left the game behind them in what was their best performance of the campaign to date.
Mary's got off to the better start when flanker Conor Oliver gathered lineout possession and supplied the platform for a promising attack. When Coleman tackled scrum half Dave Fanagan before the ball was out, Gavin Dunne split the posts with a 10th minute penalty from in front of the posts.
Lansdowne should have responded a minute later when referee Nigel Correll awarded a penalty to the home side when Tom O'Reilly was penalised in a scrum. Scott Deasy's kick swerved wide of the right hand post.
However, they did not have to wait long to be level when centre Mark Roche landed a drop goal from inside the Mary's 22. Mary's full-back Ray Crotty failed to control a kick through and Lansdowne bundled the Mary's defence over the touchline for an attacking lineout 10 metres out. But with a penalty advantage, Roche went for the drop goal to level the game 15 minutes in.
Mary's were having a lot of success with Sean McCarthy looking for Oliver in the lineout on most occasions, while Lansdowne were very quick off the line in defence. Both sides found it difficult to get any momentum with knock-ons and tough tackling preventing any real inroads by either team.
Cian Kelleher, know mostly as an attack-minded full-back/winger, showed the other side of his game with good tackles on Crotty, Chris Lilly and Marcus O'Driscoll.
Kelleher almost created a try from nothing as he broke out of his own 22 after Mary's coughed up possession from their own lineout. He weaved his way through would-be tacklers before a hand-trip from David O'Connor brought him down on halfway.
Mary's winger Lilly was sprightly all evening and after he caught a Deasy kick brilliantly, that was almost put over his head, his well-struck kick pinned Lansdowne back inside their own 22.
Lansdowne cleared their lines and although their front row were penalised at scrum time, Mary's out-half Dunne sent the resulting penalty to the right and wide on the half hour mark.
The visitors did not have to wait long for the breakthrough, though, as Deasy misjudged the flight of a Dunne box kick on his 22 and when the ball ran through off the all-weather surface, the advancing Crotty was impeded and referee Correll duly awarded a penalty try. Dunne converted to give Mary's a 10-3 advantage at the break.
Peter Smyth's men began where they left off in the opening half with young number 8 Nick Timoney making hard yards as half-time replacement Tom Daly tries to make an impact for Lansdowne.
Lansdowne had a man advantage when hooker McCarthy was sin-binned in the 50th minute for infringing at the breakdown. And it was another Lansdowne replacement who dotted down just five minutes later.
After Deasy set up a lineout inside the Mary's 22, Lansdowne's maul did the rest and Dooley crashed through in the left corner as the Mary's defence buckled under continued pressure. Deasy was off target with his conversion.
The hosts were beginning to find holes in the Mary's defence and they deservedly went ahead when the impressive winger Coleman touched down in the corner after they ran a penalty with Mary's stretched.
Coleman had a few breaks prior to this and when the ball was spread wide, he did well to finish on the left hand side. Deasy's conversion struck the right upright as Lansdowne led 13-10 with 15 minutes remaining.
Deasy added a penalty with 10 minutes to go to stretch the lead to six points, but Mary's had their chances to make one last stand.
Lansdowne were penalised twice in the final minutes, with Mary's camped on their line. But the hosts' immense defence held firm and in doing so, the headquarters club climbed to the summit following Terenure's defeat to UCD earlier in the day.
Referee: Nigel Correll (IRFU)