A 12-man Warilla withstood a late fightback to beat Berry-Shoalhaven Heads 24-18 on Saturday at Berry Showground.
The victory ensured the unbeaten Gorillas remained alone at the top of the ladder.
Despite the absence of lock Aaron Henry and halfback Luke Watts, the visitors were in control - with a 24-6 lead - midway through the second half.
But Warilla fullback Nick Lazerevski was sent to the sinbin for a professional foul and the Magpies closed the gap with back-to-back tries.
The Gorillas regrouped and put all their efforts into keeping their tryline intact over the final 10 minutes.
Warilla coach Peter Hooper said his side's bad habit of giving away penalties almost came back to haunt them.
"We were great for the first 25 minutes of the second half when we stretched that 8-6 half-time lead t0 24-6 but our discipline let us down," he said.
"The penalty count was 9-2 but the referee did his best. It was disappointing on our behalf because we lacked a bit of discipline.
"I can handle errors and things like that but when it comes to discipline, that's something we can control.
"There's no trophies handed out in May so it's not a huge concern, but we certainly have to improve that part of our game."
The Magpies have one win from four games.
"They're a good young side," Hooper said.
"They had great ball movement and we had to defend well.
"We always have trouble at Berry. I don't know what it is, whether they are turn up to play or we don't.
"Having said that, given that we were missing a couple of key players and had a bloke sinbinned ... the boys got the job done."
Premiers Gerringong continued their solid start to the season by thrashing Nowra-Gerringong 50-20 at Nowra Showground.
The Lions held a comfortable lead at half-time and finished the match strongly to register their third win.
Shellharbour won Sunday's home game against Kiama 28-16, Jamberoo beat Port Kembla 46-20 and Milton-Ulladulla beat Albion Park-Oak Flats 46-24.