Buccaneers accounted for UCD on a 23-17 scoreline at Dubarry Park. Front rowers Denis Buckley (2) and Paul Harte shared out the hosts’ three tries, with Tom Fletcher touching down for the students.
Despite being without injured captain Kolo Kiripati, Buccaneers got off to a promising start. Man-of-the-match David Heffernan got involved right from the kick-off, running hard at the UCD and laying down a marker of the hosts' intent.
Out-half Jack Carty converted a third minute penalty for Buccs and his sidestepping run opened the way for John Hayes to put his forward colleague Denis Buckley over for the first try in the 14th minute.
Carty added the conversion for a 10-0 lead and UCD, who lost number 8 Shane Grannell to an early injury, needed to regroup quickly on the rain-soaked pitch.
Their number 10 Niall Earls closed the gap with a well-struck penalty but when Heffernan won a turnover at a ruck, Buccs threaded some neat passes together for Buckley to power over for an unconverted second try out wide on the left.
UCD could not utilise their weight advantage in the scrum and Buccs continued to look sharper in possession.
Backs Alex Hayman and Mark Dolan created another opening for the Pirates and with UCD failing to clear their lines, centre Paul Harte dotted down a bobbling ball.
UCD got back in contention with an unconverted try before the break. Winger Tom Fletcher got over in the corner, running in from the halfway line as the Buccs rearguard was caught cold.
The hosts nearly hit back before referee Leo Colgan blew for half-time – Carty's well-weighted kick to the corner almost set up the bonus point score for Buccs' young winger Shane Layden, but UCD captain Andrew Cummiskey did well to cover the danger.
20-8 behind at the interval, UCD looked much more assured in the third quarter. Replacement James Thornton booted two early penalties – the second in the 50th minute – to reduce the arrears to six points.
The students threatened on the counter attack and the pressure increased on Buccs when hooker Garrett Halligan was sin-binned for illegally bringing down a maul and Thornton clipped the resulting penalty over from the 22.
It was a nervy final 19 minutes for Hendre Marnitz's home side, whose lineout faced some fierce competition from UCD's athletic forwards.
Buccs lifted the siege with some strong tackling from Carty and Callum Boland and Harte's gathering of a hacked clearance from replacement Sean Stapleton.
A final penalty from Carty, following some good work again by flanker Hayes, was enough to see the Pirates claim their third league win on the trot. Credit to UCD though, they gave it a real go in the second half and thoroughly deserved their losing bonus point.
Referee: Leo Colgan (IRFU)