Garryowen edged past a rejuvenated Shannon at Dooradoyle in a game which did not live up to expectations.
Neither side could manage a try but it was all about the result between these two great rivals and Garryowen will be relieved to maintain their great start to the campaign while Shannon picked up their first point of the season, albeit a losing bonus one.
Out half Jamie Gavin landed Garryowen's first penalty after eight minutes but it was all square after 27 minutes when Rob Guerin was on target for Shannon.
Guerin started at out half but moved to his more regular scrumhalf position when Mark Darcy was injured in the second half.
A big improvement was expected in the second half but it remained a battle of the kickers all the way.
Gavin kicked four for Garryowen and his last strike was eleven minutes from the end which left it 12-6 after Guerin had landed his second Shannon penalty.
Shannon needed a try if they were to snatch victory but they could not breach a strong Garryowen defence.
Scorers Garryowen: Jamie Gavin 4 pens.
Shannon: Rob Guerin 2 pens.
Garryowen: Ronan O'Mahony; James McInerney, Cian O'Shea, Conan Doyle, Eamon Connolly; Jamie Gavin, Neil Cronin; Rory Brosnan, James Rael, JP Cooney; Alan Kennedy, Aaron McCloskey; Shane Buckley, Anthony Kavanagh, David Sherry.
Replacements: Dave Rowley, Brendan Cullinane, Mark Hanrahan, Conor Hartigan, Geoff Ryan.
Shannon: Luke O'Dea; Richie Mullane, Eric Moloney, Willie O'Connor, Cormac O'Donnell; Rob Guerin, Mike D'Arcy; Niall Horan, Duncan Casey, Garry McNamara; Fergal Walsh, Sean McCarthy; James Murphy, John Shine, Mike Essex.
Replacements: Jason Cronin, Kevin Griffin, John Sheerin, Mike Calahane, Mark Leonard.
Referee: Paul Haycock (IRFU).
Cork Constitution 18, Dolphin 13.
Cork Constitution leapfrogged over Dolphin into third place with a deserving victory in front of a large crowd at Temple Hill.
The game was delayed for fifteen minutes because of a generator issue, but it did not affect the home side who raced into an early 8-0 lead after nine minutes.
A grubber kick into the corner saw Niall O'Driscoll touchdown after two minutes and Johnny Holland extended their advantage with a penalty.
Barry Keeshan was off target with a penalty effort on eleven minutes and gradually Dolphin began to come into the game but they had to wait until the thirty seventh minute for their first score when skipper Niall Scannell barged over the line and Keeshan converted.
The Dolphin out half was off target with a penalty on the stroke of half time but two minutes into second half he put Dolphin ahead with another penalty effort.
Con' began to dominate but Holland missed two penalty efforts before a sweeping Con' back line move saw Cathal O'Flaherty score in the corner and Holland converted to make it 15-10.
Holland extended the home side's advantage with a penalty on sixty four minutes.
Dolphin's only reward was a penalty by Keeshan two minutes before the finish to grab a losing bonus points:
Scorers Cork Constitution: Niall O'Driscoll, Cathal O'Flaherty tries, Johnny Holland con, 2 pens.
Dolphin: Niall Scannell try, Barry Keeshan con, 2 pens.
Cork Constitution: Darragh Lyons: Robert Clune, Ivan Dineen, Scott Deasy, Niall O'Driscoll; Johnny Holland, Gerry Hurley; Pat Galvin, Andrew Cudmore, John Ryan; Brian Hayes, Philip Donnellan; Graham Lawlor, Brian O'Hara, James Ryan.
Replacements: Chris Corkery, Andrew O'Driscoll, Cathal O'Flaherty, Brendan Cuttriss, Cathal Quinn.
Dolphin: Eamon Mills; James Kiernan, Cian Bohane, Danny Barnes, Gearoid O'Suillibhean; Barry Keeshan, Chris Bannon; James Cronin, Niall Scannell, Christy Condon; Chris Rowe, Dave O'Mahony; Miah Cronin, Ryan Murphy, Brian O Callaghan.
Replacements: John Cleary, John Leahy, Rob O'Herlihy, Brian Slater, Rory Scannell.
Referee: Eddie Hogan-O'Connell (IRFU).
UL Bohemian 14, Young Munster 16.
A superb try, touched down by Darragh O'Neill, who raced from his own 22 highlighted Young Munster's win over UL Bohemian at Thomond Park.
The move involved several players before O'Neill gained possession and he beat off three would-be tacklers for the try under the posts.
The conversion by Brian Haugh had Young Munster 7-5 in front with 31 minutes played.
UL Bohemian went in front after eleven minutes. Tommy O'Donnell blocked down a clearance and his fellow back rower, Ian Condell, won the race for the touchdown.
But Young Munster paid the price for indiscipline when JJ Hanrahan landed penalties after 34 and 37 minutes and just on halftime Haugh was on target for Young Munster to leave it 11-10 in favour of the home side at the interval.
Young Munster were back in front three minutes into the second half when Haugh landed a penalty and he had another twelve minutes later.
Two minutes from the end Hanrahan again kicked a penalty to give the home side a losing bonus point.
Scorers UL Bohemian: Ian Condell try, JJ Hanrahan 3 pens.
Young Munster: Darragh O'Neill try, Brian Haugh 3 pens 1 con.
UL Bohemian: Ben Martin; Martin McPhail, Mossie Lawler, Niall Kenneally, Rory White; JJ Hanrahan, Cathal Sheridan; Tom Burke, Sean Henry, Gary Walsh; Darragh Frawley, Ed Kelly; Conor Kindregan, Ian Condell, Tommy O'Donnell.
Replacements: Ed Rossiter, Alex Simpson, Sean Rennisson, Rory Cunningham, Tim Rafferty.
Young Munster: Craig O'Hanlon; Steve McCauley, Mark Doyle, Johnny Murphy, Darragh O'Neill; Gareth Quinn-McDonagh, Brian Haugh; Ger Flaherty, Ger Slattery, Darragh Cantillon; Sean Duggan, Darren Gallagher; Mark Rowley, Luke Russell, Neville Melbourne. Replacements: Johnny Moroney, Ger Burke, Alan Cotter, Luka Kunz, Mike Prendergast.
Referee: Leo Colgan IRFU
Buccaneers 32, Bruff 10.
It was another defeat for Bruff at Dubarry Park as the home side collected maximum points to keep their challenge alive.
It was 13-3 at half time.
Scorers Buccaneers: Jack Carty 2 tries, 3 cons, 2 pens, Conor Finn 2 tries.
Bruff: Try: Mike Carroll try, Brian Carroll con, pen.
Buccaneers: Shane Leydon; Mark McCrea, Conor Finn, Alex Hayman, Callum Boland; Jack Carty, Mark Dolan; Johannes Rotes, Garreth Halligan, Martin Staunton; Michael Kearney, Daniel Qualter; Luke Satchwell, Eoghan Grace, David Heffernan.
Replacements: Diarmuid Higgins, Enda O'Brien, Rory Byrne, Barry Digby, Billy Henshaw.
Bruff: Brendan Deady; Robert Finn, Mark Cosgrove, Gary Leonard, Andrew Breen; Brian Carroll, Eoghan Maher; Ger Collins, John Hogan, Colm O'Sullivan; Maurice O'Connell, Mike McCarthy; Dumani Mtya, Danny Keogh, Paddy Cleary.
Replacements: Cathal O'Regan, Michael Lynch, Mike Carroll, Richard McAuliffe, Noel Ford.
Ulster Bank League Division 1A: Clontarf 18, Lansdowne 20;
Cork Constitution 18, Dolphin 13;
Garryowen 12, Shannon 6;
St. Mary's College 16, Old Belvedere 18;
U.L. Bohemian 14, Young Munster 16;
Division 1B: Ballynahinch 31, Dungannon 13;
Belfast Harlequins 16, Ballymena 11;
Buccaneers 32, Bruff 10;
Dublin University 28, Malone 24;
U.C.D. 17, Blackrock College 19;
Division 2A: Galwegians 31, Corinthians 13;