Lansdowne lost their grip on top spot in Division 1A as Cork Constitution cruised to their first win in three league games at Temple Hill.
Out-half Tomas Quinlan's 16-point haul from the kicking tee, including three penalties in the second half and an overall return of six successes from nine attempts, helped Brian Hickey's men get back to winning ways.
The omens were good for the bottom-placed hosts early on, they quickly seized the initiative and their confidence really grew from there.
Some off-the-ball interference denied them a try straight from the kick-off, but second row Conor Kindregan – one of their Leesiders' most influential players in the early rounds – was soon driven over in the fifth minute via an Evan Mintern-won lineout.
Kindregan's second try in the space of a week was converted by Quinlan who sandwiched in a penalty between two opening strikes from Lansdowne's Scott Deasy. The latter split the posts in the eighth and 12th minutes.
Defences were on top for the remainder of the first half, despite the best efforts of Lansdowne's lively centres and Ireland Sevens team-mates John O'Donnell and Mark Roche, winger Charlie McMickan and strong-carrying lock Stephen Gardiner.
Deasy, back at his former club, missed a 19th minute penalty attempt but was back on target on the half hour mark while Constitution were without sin-binned flanker Graeme Lawler.
The visitors certainly missed the influence of captain Ian Prendiville and Leinster 'A' starters Tom Daly, Peter Dooley and Max Deegan, and they fell 15-6 behind for half-time as number 8 Willie Earle's yellow card for a high tackle was ruthlessly punished.
Good continuity from Cork Con led to full-back Shane Daly going over in the right corner in the 39th minute, with the returning Lawler and fellow flanker James Murphy linking neatly in the build-up.
Good work by Roche and hooker Tyrone Moran had Lansdowne in sight of the try-line in the dying embers of the first half, but they failed to capitalise as the nine-point deficit remained in place.
Indeed, Daly's third try of the campaign was added to by a second half score by Murphy – a breakaway effort in injury-time – with Murphy's forward colleague Brian Hayes producing a man-of-the-match performance for the victors.
Quinlan's left boot was hugely influential too, pushing Lansdowne indiscipline at almost every turn. The visitors did close the gap to 18-13 at one stage thanks to a terrific try from flanker Joe McSwiney, who played for Constitution for five years. McSwiney showed great pace and determination to break from a ruck, 30 metres out, and make the line.
However, Quinlan's dead-eye kicking form and Murphy's late five-pointer – superbly converted from the touchline – saw Con finish with a flourish, leaving Mike Ruddock's men with plenty to work on ahead of their October 28 showdown with Clontarf.
Lansdowne had a second player sin-binned in the 68th minute, centre Roche, who had switched to the wing, earning a spell on the touchline. Deasy had failed with a 43-metre penalty strike before that, and also took the wrong option when attempting a difficult inside pass after his own excellent break.
Referee: Sam Grove-White (SRU)