Michael Maguire described it as the best defensive effort he's seen in his three seasons at the club, but it could do little to take away from Nathan Merritt's attacking feats, finally becoming the club's most prolific tryscorer.

The victory was slightly soured after the match when Sam Burgess was struck in the head by a female Penrith supporter's flag, with South Sydney later complaining to the Penrith ground manager.

Burgess' mother Julie Burgess then took aim at the perpetrator on Twitter, posting "Would love to meet the woman (I'm being kind) who hit Sam with a stick as he was leaving the pitch. Sorry Penrith people but that's not OK."

Burgess played down the alleged attack when he spoke on Sydney radio station Triple M on Saturday morning.

"I don't want to make a big deal of the incident," he said. "I think Penrith and the NRL will be sorting through that one. I'm alright mate, I'm not injured."

The English international alleged the woman used her supporter's flag to hit him on the head as he walked from the field.

"I think she got a little bit excited and took her little flag to me," he laughed. "She got me on my melon - I've got a big melon so it's not hard to miss. "

"She didn't miss."

On a night that Merritt broke a five-game drought to register his 145th try for the Rabbitohs, Burgess' teammates produced one of the most resilient defensive performances in recent memory to knock over Penrith 18-2 at Sportingbet Stadium.

They were forced to defend their line for the majority of the first half and large portions of the second half, however Penrith's only points came through a Jamie Soward penalty goal.

Having slumped to three consecutive losses after their round one win against the Rooster, the Rabbitohs showed a change of attitude to topple the Dragons at the Sydney Cricket Ground last Saturday, replicating their feats on a wet night at the foot of the mountains.

"I haven't [seen better]," Maguire said of his team's defensive effort.

"I'm really proud of the players. Through a period a couple of weeks ago we probably weren't at our standard and the boys really put their heads down and spoke about their defence. Over the last two weeks they've had massive improvement and it definitely showed there tonight the way they performed in defence.

"The boys spoke about it through the week, they just wanted to stick tight together, and as they've shown the last few weeks. I'm really pleased with how the players have really come together and gone through that period that we didn't like but learnt a lot from. They've come out now and worked really hard for each other. That first half defensive effort was excellent."

The Rabbitohs missed only six tackles throughout the match, their first coming after an hour of football.

Their efforts didn't go unnoticed by the coach, who was aware of what had just unfolded when he fronted for the post match press conference.

"I heard that stat," Maguire said. "I don't think we had a missed tackle up until the 60th minute or something like that. As a coach I was pretty proud of that one. That's the hard work the players are willing to put in for each other.

"The energy they showed right through that game - we didn't get our way in the first half when we had the ball - but they came together on many occasions and committed to each other and defended really well."

Merritt became South Sydney's most prolific tryscorer, notching up try No.145 for the Rabbitohs in the second half to break a five-game drought to surpass Benny Wearing's previous club record.

"It's a great feeling at the moment," Merritt said.

"It's great to get the reward now. I've waited a good two months I think it is to score a try. I was patiently waiting ... It was just a great buzz having all the boys run over and jump all over me, it was an awesome feeling. We're just one bunch of boys and I wouldn't be able to score any tries without them being there.

"It was a bit frustrating at times, but the harder I tried to score a try the less [likely] I was going to score a try. The more I relaxed ... I got a try tonight because I relaxed and the try came to me."