Manly coach Trent Barrett has courted controversy and a possible fine for his spray at the NRL referees after his side’s controversial loss to Penrith.

In the most colourful Manly post-match press conference since Geoff Toovey’s infamous “there’s got to be an investigation” tirade four years ago, Barrett was scathing of on-field referees Henry Perenara and Chris James, and the bunker.

Barrett was incensed by the 14-4 penalty count which gifted Penrith a glut of possession and field position and the controversial decision to award Dallin Watene-Zelezniak a try four minutes before halftime.

The NRL this year tightened its rule around criticism of the referees and the bunker and Barrett walked a dangerous tightrope.

When asked if he will seek clarification from NRL referees boss Tony Archer, Barrett said: “What do you say? I’ve never seen anything like it. Ever.”

He suggested that the decisions which ran against his side cost them any opportunity to win.

“I’m so proud of the players. Their goalline defence was outstanding, it’s something we can really hang our hat on,” Barrett said.

“We’ll walk out of here feeling pretty good about ourselves. We played in circumstances where we couldn’t win when some of the things that went against us.”

The Panthers held on for victory despite not scoring a try in the second half thanks to two Nathan Cleary penalty goals.

In the wash up, Watene Zelezniak’s first-half try proved crucial with the bunker awarding the winger four points despite the fact he snatched the ball out of teammate Waqa Blake’s hands and arguably knocked it on into his teammate.

There was also a suggestion he bobbled the ball as he grounded it.

Asked if he was surprised to be awarded the try, Watene-Zelezniak told AAP: “I felt like I got it.

“But then I pulled it out of someone’s hands and it ended up being Waqa Blake’s hands.

“We were just happy to get the four points on the scoreboard.”