Kalyn Ponga was in scintillating form as Newcastle Knights thrashed struggling St George Illawarra Dragons 45-12 at Glen Willow Oval on Sunday.

Queensland Maroons full-back Ponga scored two tries and added 16 points with the boot as the Knights made it four wins in a row and consigned the Dragons to a fourth straight loss.

Mitchell Pearce boosted his hopes of a State of Origin return with a phenomenal display, which he started by sending a grubber kick beneath the posts for Tim Glasby to dot down after three minutes.

Ponga crossed in stunning fashion when he beat Ben Hunt, drove into a gap between two Dragons defenders and shook off Matt Dufty's attempted tackle as the Knights ran riot.

Pearce then created space and teed Ponga up for another dazzling run that saw him escape the challenges of Tyson Frizell and Dufty to scramble over the line.

Kurt Mann helped make it 28-0 thanks to a pass from Pearce and the half-back was at it again after the restart, sending a looping ball for Shaun Kenny-Dowall to cross in the corner before getting one of his own following an excellent run and kick by Edrick Lee.

Tariq Sims and Zac Lomax grabbed a try each in the space of four minutes, with Mann in the sin bin following persistent infringements, but Connor Watson ensured there would be no late drama when Newcastle were restored to their full complement.

Manly Sea Eagles got back to winning ways with a 24-14 victory against Cronulla Sharks at PointsBet Stadium.

A pair of Josh Dugan errors proved costly, with the full-back twice failing to gather high kicks and enabling Kane Elgey and Dylan Walker to go through.

Walker's try gave Manly a 20-point lead early in the second half and responses from Braden Hamlin-Uele and Sosaia Feki proved insufficient for the Sharks to salvage a result.