It was Bomaderry's 50th anniversary celebration, but Northern Districts spoiled the party.
In a gripping finish, the Woonona club defended grimly in the final minutes to seal a 9.11 (65) to 9.6 (60) victory at Artie Smith Oval.
Coach Leigh Forsyth praised their determination in the battle of the Tigers on Saturday.
"We were up against it, they had a great crowd there and we're a couple of goals down there going into the final term," he said.
"But the boys just kept going, they just refused to lose.
"We knew the Bomaderry game and next week against Shellharbour are big ones for us this season.
"We've got a good young group who want to stand up and be competitive every week, so it's important to gain a bit of confidence by winning close games."
Cody Haub was among their best, while Matt Stamoulos kicked two goals and Tom Strong played an important role in the final term.
It was a big day for Northern Districts, whose division two team beat Dapto by 107 points and their women's group pushed premiers Bomaderry before going down by 18.
It also keeps the Tigers in finals contention at 2-3, the same record as the Wollongong Bulldogs, who fell to Figtree at Keira Oval on Saturday.
Hamish Macdonald and Kieran Churchill showed their class, booting two goals each in playing starring roles for the Kangaroos, while Pat Walker kicked three for the Dogs.
In the other game, Kiama had 13 players on the scoresheet as they ran through Shellharbour 23.11 (149) to 1.4 (10).
The Lions, who had the bye, are the league's only unbeaten team.
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