Defending champions Clontarf became the third team to qualify for the Division 1A play-offs when they beat Cork Constitution 43-28 in a high-scoring Ulster Bank League clash on Saturday afternoon.

The north Dubliners are now guaranteed to finish third in the table, joining Lansdowne and Terenure College in the semi-finals, with Ballynahinch leading the race for fourth spot ahead of the final round of games on 11 April.

Clontarf outscored play-off rivals Cork Constitution by six tries to four at Castle Avenue, with the visitors losing their grip on an 18-15 interval lead. The Leesiders' only consolation was a try-scoring bonus point via efforts from wingers Rob Jermyn and Ned Hodson and a brace from lock Cathal O'Flaherty.

Matt D'Arcy, the Ireland Club international captain, was again in talismanic form for Clontarf, running in two tries either side of half-time to nudge the hosts ahead 23-18. Andy Wood's men were cruising when the Leinster-capped Collie O'Shea touched down and winger Max McFarland completed his brace.

Yellow cards for Rob Keogh and Adrian D'Arcy brought 'Tarf back down to earth and after Michael Brown's inviting offload put number eight Anthony Ryan over for the hosts' final try, Constitution salvaged some pride with two late unconverted scores.

Meanwhile, a strong second-half performance saw Ballynahinch overcome Dolphin on a 35-28 scoreline at Irish Independent Park, with the defeat meaning the Cork club are now relegated from the top flight.

Converted tries from Will Hanley and Niall Scannell, the second after 'Hinch lock Jonny Madden was sin-binned, had bottom side Dolphin 14-0 to the good. Ross Adair and Eamonn Mills then swapped tries before two Richard Reaney penalties cut the gap to 21-11 before half-time.

But Ballynahinch really owned the third quarter, seizing control thanks to a run of tries from dangerous backs Rodger McBurney, Jordan Grattan and Stuart Morrow. Rory Scannell converted a John Madigan score in response, only for winger Morrow to run in his second try and condemn Dolphin to Division 1B rugby next season.

The five-point return, coupled with Cork Con's loss, has 'Hinch two points clear in fourth place. Derek Suffern's charges will need to defeat Clontarf at home in two weeks' time to advance to the play-offs.

The top of the table meeting of Terenure and Lansdowne was a bit of a dead rubber, but Mike Ruddock's men claimed a 29-20 verdict at Lakelands Park to complete a season's double over second-placed 'Nure.

Lansdowne ended Terenure's incredible 29-match winning streak back in November with a late penalty from Conor McKeon, and the former Ireland Under-20 international was influential again in this rematch, kicking four crisply-struck penalties.

Three McKeon efforts, along with a 39th-minute try in the corner from promising centre Tom Farrell, had Lansdowne leading 14-5 at the break but Terenure turned around with the advantage of a big wind.

However, the visitors crucially added eight more points to their lead via an early McKeon penalty and Tadhg Beirne's 44th-minute try, which owed much to Farrell's strong running and a neat support line and offload from prop Peter Dooley.

Successive tries from Terenure centres Stephen O'Neill and Harrison Brewer, who also touched down in the first half, reduced the arrears to 22-20 with 18 minutes to go and Lansdowne prop Ian Prendiville in the sin-bin.

However, Ruddock's charges replied within five minutes through elusive winger Ian Fitzpatrick and experienced replacement Scott Deasy coolly converted into the wind to take the losing bonus point away from 'Nure.

Old Belvedere pulled off a tremendous 23-20 comeback win over UCD at Belfield thanks to Daniel Riordan's 65th-minute try and two late clutch penalties from Josh Glynn.

Young winger Glynn held his nerve to split the posts in the 72nd and 79th minutes as 'Belvo extinguished a 20-7 half-time deficit and secured a galvanising victory which has them sixth overall - three points behind 'Hinch - and still very much in the play-off picture.

Paul Cunningham's men host Terenure in the final round.

Today's 18-13 success at home to St Mary's also has Young Munster dreaming of a top four finish. They are now fifth, two points worse off than 'Hinch, and have a home game against Lansdowne to come.

Munsters seized the initiative at Tom Clifford Park with a Willie Staunton penalty and a maul try from influential number eight Sean Rennison. Mary's bounced back with an intercept effort from out-half Cathal Marsh which made it 8-7 at half-time.

A Crotty penalty three minutes into the second half was cancelled out by two tries from the Cookies as young winger Diarmaid McCarthy ran in a very well-taken score and centre Kolio Hifo added his bulk to an advancing lineout maul to touch down from close range.

Marsh answered back with a 73rd minute penalty to set up a tense finish with Mary's very much on the offensive. But a losing bonus point was the Dubliners' only reward in the end, leaving them in the promotion/relegation play-off position ahead of a final round meeting with Dolphin at Templeville Road.

Garryowen have nipped ahead of Galwegians at the top of Ulster Bank League Division 1B as the battle for the automatic promotion spot goes down to the final round.

The league organisers could hardly have scripted it better as Galwegians will close out the league campaign at home to Garryowen on Saturday, 11 April. The Light Blues will travel to Crowley Park with a one-point lead at the summit following their 34-12 bonus-point dismissal of Malone.

Notably, all five of Garryowen's tries at Dooradoyle were scored by forwards, while scrum-half Shane Kelly picked up a brace for Malone on a day when the Belfast club's relegation was confirmed.

The Cregagh Red Sox hit the front with the first of Kelly's tries, which Neil Burns converted, and Garryowen had to wait until the 26th minute for their first touchdown - finished off by prop JP Cooney following a five-metre scrum.

Jamie Gavin converted and Conan Doyle's men gained further momentum when second row Aaron McCloskey grabbed try number two just six minutes later. A penalty from out-half Gavin made it 15-7 at half-time.

Hooker Ed Rossiter and Kelly swapped tries on the resumption, but Garryowen's forward power was proving too much and excellent number eight Josh Hrstich and replacement Ben Rowley rounded off a solid team performance with two more tries, the second of which Gavin converted.

A very strong wind had quite an influence on proceedings as Galwegians' five-match winning streak was ended by Belfast Harlequins, with the hosts triumphing 36-34 at Deramore Park.

'Wegians were outscored by five tries to two during a one-sided first half as wind-backed Harlequins touched down through forwards Mark McGrath, Tom Fraser, Frankie Taggart, Sean Reidy and right winger Mark Glover. Michael Heaney supplied four conversions for a 33-5 interval lead.

Matt Brown's league leaders have pulled off a number of second-half comebacks this season, but they really had it all to do after Ulster scrum-half Heaney landed a 45th-minute penalty for 36-12.

Galwegians responded with a run of four unconverted tries and a fifth, converted this time by Aidan Moynihan, made it a two-point game before time ran out for them right at the death. Experienced centre Brian Murphy starred with a hat-trick of tries, while wily full-back John 'Luigi' Cleary helped himself to a brace.

Shannon ground out an 18-11 win at Coonagh, edging out a Ballymena side that had only pride to play for after losing crucial ground in the push for promotion.

Ritchie McMaster's early penalty had Ballymena ahead, but it was a short-lived lead as within two minutes winger Richie Mullane got in for a try out wide which David O'Donovan was unable to convert.

Ian Sherwin's home side missed a couple of scoring opportunities with a foot in touch and a missed penalty from Tadhg Bennett, and a second three-pointer from McMaster had the Braidmen leading 6-5 at the break.

Shannon resumed in fine fettle, though, taking the game to the visitors.

Bennett split the posts five minutes in and replacement Niall Horan touched down after a bout of forward pressure in the 55th minute.

Ballymena hit back with an unconverted effort from centre Paddy James, only for Shannon to have the final say with a decisive penalty from Bennett nine minutes from the end.

At Dubarry Park, UL Bohemians made it three victories for the division's Limerick clubs as they ensured their Division 1B status for another season with a 32-0 whitewash of Buccaneers.

Relegation-threatened Bohs needed a big performance and they got just that, securing their first try-scoring bonus point of the season with five of their backs crossing the midlanders' line.

Disappointing Buccs trailed 15-0 at half-time despite having a good deal of possession.

Out-half David Johnston opened UL's account with a 21st-minute penalty and right winger Colin Ryan scampered over out wide for a try.

Bohs' second touchdown was scored by Rory White before the break, but his centre partner Darren Moroney saw yellow for a tackle offence and some scrum issues saw the sides lose a prop each to the sin-bin.

However, the visitors continued to play with the greater cohesion and they built for a very strong finish as they ran in three late tries.

Moroney got over by the posts in the 70th minute, replacement Robbie Bourke followed him over the whitewash and then a tidy cross-field move saw veteran full-back Mossy Lawler dot down in the final play.

Corinthians will join Malone in dropping down a division after they were beaten 32-11 by Dublin University at Corinthian Park.

Connacht's Ultan Dillane scored the bottom side's only try as they fell to their 13rd defeat of the league season.

The result saw third-placed Trinity, the division's highest scorers, maintain their push for promotion.

Flanker Brian du Toit scored a brace of tries and fellow forwards Nick McCarthy and Richard Halpin and full-back Jack Fitzpatrick also touched down.