Penrith are one win away from their first NRL grand final in 17 years after defeating the Sydney Roosters 29-28.

Nathan Cleary scored a first-half hat-trick and kicked a crucial field goal as the Panthers held on to win.

It took their winning streak to 16, making for the third biggest of all-time.

But it wasn't all smooth sailing for the Panthers, with Viliame Kikau facing a possible ban for a dangerous tackle that threatens his preliminary final availability.

For the Roosters, they must now do it the hard way via a sudden-death semi-final between the winner of Canberra and Cronulla.

[Source: https://www.tvnz.co.nz/]