Belfast Harlequins moved within striking distance of Ballymena at the top of Ulster Bank League Division 1B after beating their Ulster rivals on Friday.
In a game dominated by the elements, Ballymena failed to take advantage of a strong wind at their backs in the first half at Deramore Park.
The opening 40 minutes contained no scores, with Ballymena winger John Semple missing an early penalty won by hooker Jonathan Burns.
The wet and windy conditions worsened as the minutes ticked by and a lack of quality ball left both back-lines underused.
Most of the play was dictated by the packs, tough and uncompromising tackling was the order of the day and every inch was fought for in this well-contested derby tie.
Former Ireland Under-20 international Ian Porter, kicking in the absence of ‘Quins top scorer Michael Heaney, fired over his first successful penalty in the 46th minute following a high tackle.
Porter missed the target shortly afterwards but two further successes after 63 and 73 minutes helped Adam Larkin’s men record a confidence-boosting win at the start of the New Year.
‘Quins also had a try disallowed in the final quarter as they pressed for more points – replacement Michael Ferguson was adjudged to have knocked the ball on over the line.
But Ballymena could not respond despite the best efforts of Richard Aingworth, Blane McIlroy and captain Paul Pritchard, and a late penalty miss from Porter was the last of the scoring chances.
Referee: David Wilkinson (IRFU)