Ballynahinch 7 UCC 13, Ballymacarn Park
Barnhall 16 Thomond 9, Parsonstown
Bective Rangers 6 Dublin University 31, Donnybrook
Buccaneers 8 Clonakilty 3, Dubarry Park
Highfield 22 Old Crescent 10, Woodleigh Park
Suttonians 15 De La Salle Palmerston 35, JJ McDowell Memorial Grounds
Wanderers 9 Belfast Harlequins 25, Merrion Road
Young Munster 16 Malone 14, Tom Clifford Park
The starting line-up which coach Conor Twomey selected was perhaps the youngest in the history of UCC senior rugby, with one 21-year-old and the remaining 14 players either part of last season's Under-20 squad or still in school.
They showed a maturity beyond their years, with their defensive resolve allowing them to valiantly hold onto their lead and see out their third successive league win over Ballynahinch.
UCC had the benefit of a strong wind in the first half and while 'Hinch dominated possession wise, they could not put points on the scoreboard. It was the visitors who took the lead in the 28th-minute when out-half Gavin Dunne flung an excellent 40-metre penalty through the posts from wide out on the left.
Dunne's second successful place kick followed seven minutes later, from a more central position, to hand his side a 6-0 interval lead. Would it be enough with 'Hinch being wind-backed in the second half?
'Hinch had the visitors under constant pressure for the third quarter. A Mark Scott penalty drifted wide of the uprights but after a succession of scrums, the UCC pack gave way and referee Dudley Philips awarded the hosts a 62nd-minute penalty try which full-back Scott converted.
On the restart, UCC had influential flanker Dave Nathan sin-binned for taking out Stuart Lamb. The momentum was well and truly with 'Hinch now, with a 7-6 lead and a man advantage.
But the County Down men succeeded in making a number of poor decisions. They persisted with running the ball rather than kicking for the corners and heaping the pressure on their young opponents.
They paid the price as the game entered its final ten minutes. 'Hinch scrum half Harry McAleese had his clearance kick charged down by Dunne and the UCC number 10 raced through to gather and touch down for a vital seven-pointer.
The visitors' defence held out over the closing 15 minutes for a famous UCC victory. A poor second half display let 'Hinch down badly and with the wind behind them after the break, Derek Suffern's men will be kicking themselves that they only gained a losing bonus point from this encounter.
At Dubarry Park on Saturday, Buccaneers won their first match back in Division Two with an 8-3 dismissal of Clonakilty. Connacht number eight Colm Rigney scored the game's only try with Buccs' Ireland Under-20 hopeful Alan Gaughan trading a penalty with Clonakilty out-half Gary Cribb.
Former Leinster, Munster and Ireland half-back Brian O'Meara got amongst the tries as Highfield claimed a 22-10 victory in Geoff Moylan's first league match in charge of the Cork men.
Tries from assistant coach O'Meara, captain Dave Ryan and new signings Michael Essex and Jonathan Bradling Harris saw Highfield get the better of a valiant Old Crescent side.
Belfast Harlequins scored their third win in three AIB League meetings with Wanderers as tries from Darren Cave, Niall Conlon and Paul McKenzie inspired them to a 25-9 triumph at Merrion Road.
Ulster centre Cave opened the scoring in the fifth-minute after a Wanderers clearance kick was charged down. Niall O'Connor, another member of the current Ulster squad, converted before David Fitzgerald made up for two earlier misses with a precise 37th-minute penalty.
Turning around with a 7-3 buffer, O'Connor kicked 'Quins seven points clear before he was sin-binned for being offside at a ruck. Fitzgerald kicked the resulting penalty but that effort was cancelled out by a 50-metre penalty strike from the visitors' right winger Willem Slabbert.
After another Fitzgerald penalty success, Andy Ward's men tightened their grip on the game, twelve minutes from time, when prop Conlon did well to shrug off two tackles and charge over for his try.
Wanderers were caught out in the closing minutes when just they seemed to be making headway in the 'Quins 22 with a series of rucks and mauls. Unfortunately for the Dubliners, a pass was intercepted by 'Quins winger McKenzie and the former Ireland Under-21 international had enough pace to dash 80 metres to the try line, allowing O'Connor an easy convert.
At Parsonstown, Barnhall began their seventh season in Division Two with a 16-9 win over Thomond. A sizzling second half performance from Dublin University saw them to a 31-6 success over Dublin rivals Bective at Donnybrook.
Paul Gillespie, Killian Stafford (2), Volney Rouse and Richard Morrow shared out the Trinity tries. The bonus point victory sent Tony Smeeth's charges to the top of the table.
Meanwhile, four tries and 15 points from the Phil De Barra handed De La Salle Palmerston a 35-15 win over their first ever league visit to Suttonians.
New Zealand-born out-half Tom Wells kicked three penalties and converted centre David Corcoran's try as Young Munster accounted for Malone by 16-14 at Tom Clifford Park.
Malone almost took the lead in the second-minute but flanker DW Bekker was held up short on a close range drive. Young Munster did take the lead midway through the first half when Malone full-back Johnny Burgess was charged down and a swift attack ended with Corcoran touching down.
A penalty from former Ireland Under-21 out-half Kieran Hallett reduced the gap for the visitors to 7-3 at the break.
Wells and Hallett swapped penalties at the start of the second half before Malone prop David Halliday muscled over for an unconverted try, leaving the score at 11-10 in the Ulster side's favour.
However, Wells booted two more penalties to a single effort from Hallett and the Kiwi's accurate place-kicking was enough for the Cookies to start the new campaign with a win.