Young Munster's looked on course to get back to winning ways at Musgrave Park after last week's shock defeat at home to St. Mary's when they led Dolphin 10-0 at half time with a try from Ger Flaherty and a conversion and penalty by Willie Staunton.
Things went horribly wrong for the Limerick side in the second half as they lost their discipline and conceded two penalty tries. Eric Moloney and Dave O'Callaghan also scored tries to secure a winning bonus point and Barry Keeshan converted three of the tries.
Munster replied with a try from Mark Doyle and Staunton added a conversion and penalty.
Scorers Dolphin: Penalty Tries 2, E Moloney, D O'Callaghan tries, B Keeshan 3 cons.
Young Munster: G Flaherty, M Doyle tries, W Staunton 2 cons, 2 pens)
St Mary's College 21, Cork Constitution 8.
It was a brave effort by Cork Constitution but a high flying St Mary's side proved too strong for them at Templeville Road and have extended their lead at the top of the table as the league reaches the half way stage.
Mary's played with a strong wind in the opening half and led 11-0 at half with two penalties from Gavin Dunne and a try by Hugh Hogan following a forward drive.
Niall O'Driscoll got Con' back into the contest with a try on fifty five minutes but Dunne and Gerry Hurley exchanged penalties.
With the final play of the game and Con' holding on for a bonus point, a clearance inside the Con' Twenty Two was blocked down and substitute Damien Hall pounced to score and Dunne converted.
Scorers St Mary's: H Hogan, D Hall tries, G Dunne 3 pens con.
Cork Constitution: N O'Driscoll try, G Hurley pen.
St Mary's: G Dunne; D Hudson, S Grissing, M Sexton, C Lilly; P Brophy, M D'Arcy; J McGrath, Richard Sweeney, Robert Sweeney; G Logan, S Bradshaw; C Ruddock, G Austin, H Hogan (c).
Replacements used: C McMahon, D Hall.
Cork Constitution: S Scanlon; C Quinn, S Deasy, I Dineen, N O'Driscoll; J Holland, G Hurley; M Gately, A Cudmore, C Corkery; B Hayes (c), I Nagle; J McSwiney, B O'Hara, J Ryan.
Replacements used: K Stokes, B Cagney, C O'Flaherty.
Bruff 22, UCC 18. (Cormac Liddy)
The two clubs at the bottom of the table provided a rousing contest at Kilballyowen before Bruff emerged winners to keep alive their prospects of avoiding relegation.
But for UCC the signs are ominous and the concession of two tries early in the second half after they had a player in the in the sin bin had a critical bearing on the outcome.
Bruff dominated in the first five minutes and were rewarded for their strong scrum when UCC were penalised for not binding properly and Brian Cahill popped over the penalty after six minutes.
The lead was short lived, only three minutes when UCC capitalised on slack midfield play by the home side and Mike Linehan broke down the centre of the pitch to touchdown for a try that Brian Kingston converted.
Bruff were in trouble again after fifteen minutes. This time they lost their own throw in a line-out and when UCC gained possession they moved the ball wide and this time Brian O'Callaghan grabbed a try that was not converted but they remained 12-3 in front at the interval.
The sin binning of Dave Horan in that half did not have as big an impact on the outcome as did the sin binning of UCC's Willie Ryan two minutes into the second half.
While he was out of the action Bruff managed two tries. The first came immediately after the sin-binning when the Bruff pack drove over and number 8, Padraig Cleary, got the touchdown.
Bruff went back in front when Mark Cosgrave got in after six phases of play by the pack culminated in Brendan Deady superbly grabbing an overhead pass and he sent Cosgrave over. Brian Cahill converted.
When Bruff were penalised for off-side Kingston landed the penalty to make it 15-15.
Ten minutes from the end Bruff's forwards were rewarded for their efforts. They forced two five metre scrums in rapid succession and in the second of them UCC were penalised.
John Shine took a quick tap penalty and raced away to his left until he found the gap to dive in for the try which Cahill converted to clinch a badly needed win for the County Limerick side.
Scorers Bruff: P Cleary, M Cosgrave, J Shine tries, B Cahill 2 cons, pen.
UCC: M Linehan, B O'Callaghan tries, B Kingston 2 pens, con.
UL Bohemian 16, Ballynahinch 20 (Cormac Liddy)
Table toppers Ballynahinch got a second half scare from UL Bohemian at Annacotty but they had done enough to win by the time the home side managed two tries.
The visitors led 17-3 at the interval after UL Bohemian made a dreadful start.
Their troubles began as early as the sixth minute when James Thompson made an interception and raced clear untouched for a try that James Lash converted.
This was followed by a second try when Stuart Morrow broke through the middle and touched down and again Lash added the points.
All the home side could manage was a penalty by JJ Hanrahan and it looked as if Ballynahinch would run riot in the second half.
But UL Bohemian responded well and ten minutes into the second half Ben Martin rounded off a splendid move with a try which was followed by another Hanrahan penalty. Lash put over a penalty to edge the visitors to their 20 points but midway in the half Fergus Ahern had another UL Bohemian try.
In a frantic finale the home side pressed for another try but had to be content with the losing bonus point.
Scorers UL Bohemian: B Martin, F Ahern tries, JJ Hanrahan 2 pens.
Ballynahinch: J Thompson, S Morrow tires, J Lash 2 cons, 2 pens.
Ulster Bank League Division 1A: Clontarf 35, Old Belvedere 7;
Dolphin 26, Young Munster 20;
Lansdowne 55, Blackrock College 13;
St. Mary's College 21, Cork Constitution 8;
Division 1B: Ballymena 13, Dungannon 39;
Bruff 22, U.C.C. 18;
Buccaneers 12, Galwegians 6;
U.C.D. 22, Belfast Harlequins 39;
U.L. Bohemian 16, Ballynahinch 20;
Division 2B: Connemara 16, Wanderers 13;