Parramatta were the roadkill in the opening round before the Panthers made it 2-nil to start their 2018 campaign, defying stifling conditions to reel in the Rabbits 18-14, only hitting the front for the first time five minutes from full-time.

Anthony Griffin is in rare form in the coaching box. After keeping Viliame Kikau on ice last week to ensure he played a decisive role in the second half, this time he held back Tyrone Peachey, who was only given the green light with 20 minutes to play.

Before that, he had paced up and down the sideline desperate to get on the park, while the home fans were chanting his name to try and convince the gaffer to let him loose.

It was worth the wait. With an exhausted Souths missing captain Greg Inglis for most of the second half with a concussion, the Panthers smelled blood to work their way to within striking distance thanks to tries to Trent Merrin and Waqa Blake.

Then Peachey would get his moment, flying on to the ball to reach over and give Penrith, a side much-maligned in the off-season, the ideal start to their season.

"We were positive and calm at half-time, obviously confident in our ability," Griffin said.

"We didn't want to be down by that score but it's an 80-minute game. I always thought we'd get our chances and when we did, we took them.

"They didn't let the scoreboard get into their head. If we had the scoreboard in our head, we would have got beat.

“We don't want to be in that position but they took a bit of running down.

"They never give up. I'd rather that character in our side at the moment than playing flashy and get beat."

Nathan Cleary's streak of 31 consecutive successful kicks ended late in the match but the young halfback turned it on when his side needed to find something extra.

He tapped into his running game and was highly influential late in the contest. His Origin stocks have only grown over the opening weeks of the NRL season.

Souths were brave and at times adventurous with the ball but are still waiting for their first win in the Anthony Seibold era.

Damien Cook was brilliant from dummy half and Cody Walker shone at five-eighth but the cool head of injured halfback Adam Reynolds was sorely missed.

Souths stuttered badly at the start, giving away three penalties in as many minutes to ensure they spent the opening exchanges defending their line.

They withstood repeated raids and after a penalty to rookie seven Adam Doueihi, they set the park on fire with a brilliant 90m movement, capped off by Walker as he gave them an 8-nil lead.

Penrith were just clinging to life at that point. Inglis was held up in the 35th minute, then Josh Mansour managed to stop Dane Gagai at the death.

But Cook, who could sense the Penrith big men fading in the 30-plus degree temperatures, spotted a gap, then blasted through to give his side a 14-nil lead going into half-time.

It wasn't enough last week and wouldn't be this time either. Inglis was the first casualty as Penrith took control of possession and momentum.

Merrin had to reach out backwards in the 52nd minute but finally got his side on the board.

The energy for Penrith was notable as the crowd lifted them back into the contest, while Souths were down to a two-man bench as Tevita Tatolo joined Inglis in the line for a HIA.

Blake crossed for his third try of the season with 15 minutes to play and Cleary obliged with the conversion to have Penrith trailing 14-12 with 15 minutes to play.

By now, Peachey was looking for any possible way to get involved and was in the right spot at the right time, although the finish took skill and strength.

Souths threw the kitchen sink at Penrith for the final five minutes but every raid was snuffed out.

They remain winless, although far from hopeless, while Penrith can go 3-0 next week if they beat the Bulldogs.