Liam Martin was in rival Cameron Munster's sights ahead of their grand final clash but ended up trouncing the Melbourne five-eighth to win his maiden Clive Churchill Medal in Penrith's 14-6 grand final victory.

Munster earlier in the week said the pair didn't get along when they have been together in Australia camps and admitted that Martin had previously got under his skin.

The Penrith forward got under his ribs early on in Sunday's clash at Accor Stadium, setting the brutal tempo of the match with a bone-crunching hit.

"Marto's the epitome of a big game player," coach Ivan Cleary said.

"The bigger the game, the better he goes. Just some huge plays tonight, he was out on his feet. He just kept finding something, just the way he plays, it's all effort, all action. There's more than that too, his skill. He continually turns up when we need him."

Martin was pivotal to the Panthers' victory.

He scythed past Munster after collecting a short Nathan Cleary pass late in the first half to score the try that gave his side the lead.

The 27-year-old had another massive contribution in the second period with his side ahead by four points.

Martin leapt above Melbourne's aerial weapon Xavier Coates under a raking Cleary bomb and came down with the ball, which eventually ended up in the hands of centre Paul Alamoti who scored in the corner to seal Penrith's fourth-straight premiership.

But his brutal tackling and fearless running throughout were just as impressive as he joined Luke Lewis, Craig Fitzgibbon and Gorden Tallis as the only other second-rowers to have been named the best player in a grand final in the NRL era.

His one-on-one strip on Jack Howarth in the second half came at a crucial time as the Storm were gaining ascendancy and his 43 tackles were integral to his forward pack's dominance.

"Oh wow. It's so surreal," Martin said as he collected his medal.

"I just want to congratulate the Storm on a fantastic year. I've got the utmost respect for you guys, you're just there every year.

"To our boys, I love you so much. Just shows the character we have to dig deep, and I was gone then but to have you boys drag me along. I adore you guys, the fans. Just love you guys.

"Thank you so much. We do it for you, we do it for Penrith. Love yous."

Nathan Cleary said the performance was up there with one of Martin's best in a Penrith jersey.

"I've been playing with Marto since we were 17, so to see him come this far, I'm pretty proud of him," he said.