Clontarf kept up the pressure for honours in Division 1A when they ran out 26-9 winners over Young Munster at Clifford Park.
But it was only in the last ten minutes that they shook off the shackles of a home side who looked on course for a losing bonus point when they trailed 9-14.
On a pitch that was a credit to the Young Munster ground staff it seemed as if their efforts might bring a big reward when Brian Haugh put them in front with a penalty after only three minutes.
The lead lasted only three minutes when David Joyce punished Young Munster for being off-side when he landed a penalty and he put his side in front midway in the half when Young Munster were offside in the middle of the park.
A scrum infringement after 34 minutes cost Young Munster another three points when Joyce was again on target. Just as he did in the first half Haugh landed an early penalty but a try by Sam Cronin after 63 minutes brought a bit of daylight between them.
But another Haugh penalty brought Young Munster back into contention.
When a Young Munster player went in at the wrong side to bring down a maul it yielded a penalty try for 'Tarf who had a try two minutes from the end by man of the match David Joyce who brought his tally to sixteen points.
Cork Constitution defeated U.C.D. 14-6 at Temple Hill in a dress rehearsal of their upcoming Bateman Cup Final. A try by Darragh Lyons and a Gerry Hurley penalty had the home side 8-6 ahead at the interval. Two long range penalties from Chris Quinn denied the visitors a losing bonus point.
Dolphin eased their relegation worries with a 13-0 away win over Ballynahinch. The visitors led 7-0 at half time with a penalty try which Barry Keeshan converted and Keeshan added two penalties after the break.
Three penalties from Alan Gaughan was not enough for Garryowen who lost 13-9 away to defending champions Lansdowne.
In Division 1B U.L. Bohemian hopes of promotion received a set back when they lost at Annacotty to leaders Terenure College 15-6.
James O'Neill pounced for three tries to give Terenure the points.
O'Neill had the only score of a first half which saw a player from each side pick up a yellow card for separate misdeeds and when Robbie Burke kicked a penalty for the home side two minutes into the second half hopes of a bonus point rose.
But O'Neill got in for two more tries and a second Burke penalty could not salvage a losing bonus point for the home side.
The Blackrock College v Shannon game at Stradbrook was abandoned early in the second half because of an injury.
In Division 2A leaders Galwegians extended their lead with a 23-17 home win over U.C.C.
Cashel caused an upset with an 8-7 away win over second placed Ballymena.
At the other end of the table Highfield moved out of the relegation places with a 15-10 home win over Seapoint. A penalty try and a try by Ben Murphy and a conversion and penalty by Ian O'Donoghue in the opening half was enough for the home side.
Old Crescent now occupy second last spot after their 9-3 away defeat by Bective Rangers.
Bruff recorded their first win of the season with a 26-15 away win over Naas, but still occupy last spot.
In Division 2B leaders Nenagh Ormond dropped their first points when they drew 15-15 at home to Navan.
Thomond moved ahead of Greystones with a 16-3 win at Liam Fitzgerald Park. Ger Finucane and Brendan Guilfoyle were Thomond's try scorers and Dermot Fitzgerald kicked two penalties.
Richmond won their relegation clash at Musgrave Park with a 13-7 victory over Sunday's Well. Paul Giraudet opened the scoring with a try for Sunday's Well which Shane O'Riordan converted. Eoin Hanley replied with a try for Richmond which Wayne Murphy converted to leave the sides level 7-7 at half time. Murphy kicked two second half penalties to secure victory for the visitors.
Midleton eased their relegation worries with an 11-6 home win over Instonians. A try in the corner from Jaydee Cruickshank and two penalties from Christian Walker in the opening twenty minutes was enough for the East Cork side to seal a return to winning ways at a crucial stage of the league. (Additional reporting by Jason Boyle)
Ulster Bank League Division 1A: Ballynahinch 0, Dolphin 13;
Cork Constitution 14, U.C.D. 6;
Lansdowne 13, Garryowen 9;
Old Belvedere 22, St. Mary's College 22;
Young Munster 9, Clontarf 26;
Division 1B: Blackrock College v Shannon abandoned;
Buccaneers 18, Belfast Harlequins 19;
Dungannon 3, Malone 13;
Galway Corinthians 23, Dublin University 22;
U.L. Bohemian 6, Terenure College 15;
Division 2A: Ballymena 7, Cashel 8;
Banbridge 28, City of Derry 13;
Bective Rangers 9, Old Crescent 3;
Galwegians 23, U.C.C. 17;
Highfield 15, Seapoint 10;
Naas 15, Bruff 26;
Queens University 18, Old Wesley 10;
Rainey Old Boys 13, N.U.I.M. Barnhall 8;
Division 2B: Ards 19, Skerries 12;
City of Armagh 14, Boyne 6;
D.L.S.P. 12, Sligo 10;
Midleton 11, Instonians 6;
Nenagh Ormond 15, Navan 15;
Sunday's Well 7, Richmond 13;
Suttonians 8, Tullamore 24;
Thomond 16, Greystones 3;