Newcastle will meet Penrith next Sunday in a preliminary final after defeating the New Zealand Warriors in a thrilling contest.
Fullback Kalyn Ponga passed his head injury assessment after leaving with concussion symptoms less than seven minutes before full-time.
Fox Sports confirmed the result shortly afterwards, with Ponga saying he felt good and expected to play the following week.
Newcastle's key attacking player made 23 carries for 208 metres, a line break and 16 tackle busts.
"I'm just proud. I feel like crying. Everyone counted us out five or six weeks ago, but we are just representing the team with so much pride. It's an awesome feeling."
The Knights have seven days to recover before facing the Panthers, having already overcome the absences of Jacob Saifiti and Dylan Brown.
Dylan Lucas also returned from a gruesome ankle injury off the bench.
Had Ponga failed his assessment, he would have been ruled out for at least 11 days.