Gosford recorded their second narrow victory in the space of three weeks after scoring seven-goals-to-one in the third quarter against Cardiff at Adcock Park on Saturday.
The Tigers (11.9-75) edged out the fast-finishing Hawks (10.12-72) by three points in the men's Black Diamond Cup after leading by 25 going into the last term.
In what proved to be a hard-fought encounter, Gosford were up by three at the first break but down by 10 at half-time.
The Tigers then piled on 43-points-to-eight in the ensuing period before Cardiff responded with six majors on the run home.
Gosford's previous win a fortnight ago came after holding off Wyong Lakes by two points.
The Tigers have lost by less than three goals on three occasions this year, inlcuding Warners Bay last start and Killarney Vale in the season opener.
Eighth-placed Gosford (12 points) now move within two competition points of Cardiff (14), who sit equal sixth on the ladder with three rounds remaining.
Warners Bay (14) joined the Hawks on the overall standings with Dillon Walsh-Hall and Zach Lauritsen kicking five majors each as the Bulldogs (15.13-103) beat Maitland (7.7-49) at Feighan Oval.
Singleton (14.15-99) staved off fifth-placed Nelson Bay (6.10-46) and earned outright third spot after second-placed Newcastle City (9.13-67) accounted for Killarney Vale (6.14-50), who slip to fourth.
League leaders Terrigal Avoca (19.27-141) maintained their perfect record for 2020 by easily disposing of Wyong Lakes (1.1-7).
In round nine of the women's Black Diamond Cup it was Killarney Vale, City, Terrigal Avoca and Maitland in the winner's circle.