[2] Out of favour at Fulham, Mahoney joined Fourth Division club Northampton Town on loan in October 1981 and made six league appearances without scoring.
[1][3] Partnering Francis Joseph up front, Mahoney had a good start to life at Griffin Park, scoring 15 goals in his first 28 appearances and signing a permanent contract,[4] before suffering a fractured leg in an FA Cup second round replay versus Swindon Town in December.
[6] He was part of the team which secured promotion to the Premier Division and won two cups during the 1987–88 season, with Mahoney's striker partnership with Micky Welch being regarded as the most-feared in non-League football.
[9] Mahoney was also part of the Canvey Island team which went on a run to the first round proper of the 1995–96 FA Cup,[10] when they took Second Division club Brighton & Hove Albion to a replay before going out.
[3] Mahoney married his wife Michele on Saturday 21 February 1981 in Grays and together with best man Kevin Lock,[13] he played for Fulham later that day.