Kalyn Ponga suffers another concussion as Sydney Roosters hammer Newcastle Knights 42-12

Ponga was hit high in a reflex tackle by Roosters prop Matthew Lodge in the eighth minute and immediately crashed to the turf.

He appeared wobbly on his feet as he received treatment and was taken off for a head-injury assessment, which he failed.

It was the fifth time this season the dynamic fullback has required a HIA.

He was stood down for a game after copping a high shot from NSW halfback Nathan Cleary in Origin II, two weeks after he was knocked senseless in Newcastle's loss to Penrith on June 12, attempting to stop rampaging back-rower Viliame Kikau from scoring a try.

On that occasion, he was unable to return to the field but backed up a week later against the Raiders in Canberra.

He also required HIAs during Newcastle's losses to Manly on April 7 and Parramatta on April 24, but on both occasions was able to play on. The 24-year-old has undergone HIAs on more than 10 occasions over the past four seasons.

In Ponga's absence, five-eighth Anthony Milford moved to the last line of defence and utility Phoenix Crossland came on to play pivot.

The Roosters showed no mercy against a Newcastle team minus their main attacking weapon.

They led 16-2 at half-time after tries by five-eighth Luke Keary, winger Joseph Suaalii and skipper James Tedesco, and increased their advantage to 22-2 seven minutes after the break when winger Daniel Tupou scored.

When Suaalli flashed over for his second try in the 53^rd minute, Newcastle were facing another blowout loss in their own backyard.

The Knights have now lost seven of their nine games at home this season to remain 13^th on the ladder.

Newcastle's cause was not helped when back-rower Lachlan Fitzgibbon left the field with an apparent shoulder injury, and then centre Dane Gagai was sin-binned for verbally abusing referee Peter Gough.

Late tries by Crossland and Edrick Lee provided Knights fans with some consolation.

The win lifted the Roosters from 10^th into the top eight.