Sunia Turuva has bagged the first hat-trick of his NRL career as Penrith overcame Nathan Cleary's absence for a 22-16 defeat of the fast-finishing Sydney Roosters.
Talismanic halfback Cleary (hamstring) joined Scott Sorensen and James Fisher-Harris in the casualty ward for Thursday's clash at Allianz Stadium and could miss up to a month.
But all signs are that the Panthers will be able to keep their premiership defence on track without the general after they unleashed their suffocating best on the Roosters.
"I was very proud," said Panthers coach Ivan Cleary.
"When you've got players out, or there are key combinations that are changed, it's going to test your systems and your culture.
"(But) we pretty much did everything we wanted to do throughout the game."
Dylan Edwards orchestrated the early 14-0 lead that proved pivotal and stand-in halfback Brad Schneider ably handled Cleary's workload with the boot on club debut.
The Roosters were left to rue an error-prone start and a no-try call that proved significant, given the final margin.
Joey Manu scored what would have been the Roosters' first try, only for decoy runner Jared Waerea-Hargreaves to be ruled as having obstructed Edwards.
But once off-contract Turuva struck twice in five minutes after the break, the Tricolours had it all to do down 22-6.
Tries from Brandon Smith and Daniel Tupou put some respectability on the scoreboard in the final six minutes, but it was too late for the Roosters to avoid a ninth-straight loss to the Panthers.
"I like the fact we had the ability to go after it at the end, to hold it that close, but we were well beaten in a lot of areas," said Roosters coach Trent Robinson.
"We just had a wide range in quality tonight. We didn't collectively get to a team attitude where we could rally and do what we wanted to do."
In his first game playing the role that made stars of Sean O'Sullivan and Jack Cogger, Penrith's back-up halfback Schneider put in the kick that helped Turuva to his first try of the night.
Joseph Aukuso-Suaalii fumbled Schneider's cross-field bomb to the deck, with Edwards passing to an unmarked Turuva 10 minutes into the contest.
Schneider was Cleary-like in his kicking thereafter as the Panthers easily controlled the battle for territory.
After nailing the sideline conversion that followed Turuva's first try, Edwards grubbered through the line for the visitors' second.
Edwards finished the night with 258 run metres in another workmanlike performance.
The Roosters had few answers to Penrith's steely defence, though they would have taken comfort from their ability to draw blood once in position.
On their first foray into the red zone, Joey Manu's would-be try was scrubbed for an obstruction, and on their second just before the half, Sitili Tupouniua touched down from a Sam Walker kick.
But the Panthers' right side, brutal to start the season, continued to smell blood after the break and Turuva cashed in after the ball twice went through hands.
Penrith's State of Origin second-rower Liam Martin suffered a right shoulder injury in the opening 10 minutes but was able to return in the second half.
Son of Penrith club legend Mark, Mavrik Geyer received a cheer from the crowd when he came on for his NRL debut with 30 minutes to play. He finished with 48 run metres.