Wayne Bennett did his old, and soon-to-be new, club Brisbane a massive favour at Hunter Stadium on Saturday by masterminding Newcastle's 42-12 dismantling of Parramatta, leaving the Eels' finals hopes hanging by a thread.

Parramatta's seventh straight loss to the Knights left them in ninth position, equal with the Cowboys and Broncos on 28 points but well behind on points differential, and the seventh-placed Cowboys have a game in hand against last-placed Cronulla (14) in Townsville on Monday night.

The Eels now need to hope the Storm beat the Broncos in Melbourne next Friday then do their bit by beating the Raiders in Canberra next Saturday, and also hope the Warriors (26) do not win both their last games against the Titans in Auckland on Sunday and Panthers in Penrith seven days later.

The Broncos, where Bennett will return next season, stayed alive by beating the Dragons 30-22 at Suncorp Stadium on Friday night and are back in control of their own destiny, needing to beat the Storm to return to the finals.

In front of a crowd of 18,558, the Knights trailed 12-8 at half-time after running into a strong southerly for the first 40 minutes, but responded with six second-half tries in a flurry of 34 unanswered points to register their fourth straight home win after previous victories over the Warriors, Storm and Roosters.

The Knights were forced to make a late change when hooker Travis Waddell became ill during the warm-up, giving Tyler Randell a chance to make his NRL debut.

Newcastle's disrupted start became disjointed when Tyrone Roberts tried a short kick-off but could not make the 10 metres into a strong southerly, gifting the Eels a penalty and prime field position.

A Newcastle handling error compounded that indiscretion, Chris Sandow found space on his right, Will Hopoate stepped inside some frail defence to score, and Sandow converted for a 6-0 lead in the fourth minute.

The Knights regrouped with unconverted tries by rookie left winger Sione Mata'utia in the 17th and 25th minutes to take an 8-6 lead.

The second of those tries came after the Knights shifted the ball from the right edge to the left through seven pairs of hands before 18-year-old Mata'utia planted the ball down just before he was bundled into touch.

Jarryd Hayne was subdued for much of the first half, with his only trick shot coming in the 32nd minute when he bent down to tidy up a Kurt Gidley grubber kick and scooped up the ball from between his legs.

Newcastle looked like hanging on to take a two-point lead to the break but Gidley spilled a wayward Roberts pass to give the Eels a sniff.

Sandow made them pay with a deft short pass to back-row tear-away Tepai Moeroa, who lost a boot but still trampled over Gidley and Korbin Sims to crash over near the posts.

Sandow's conversion gave the Eels a 12-8 lead and threatened to extend that when he picked up a loose pass and scooted 50 metres before Roberts rounded him up.

Sims did not return for the Knights after being helped from the field in the 37th minute suffering concussion, coming off second best after trying to tackle David Gower.

Jarrod Mullen slid over to score in the 50th minute and Gidley converted for a 14-12 lead.

The Knights were unlucky not to add a penalty goal after Tim Mannah flopped on Mullen after the try but Adam Devcich dismissed Newcastle's claims for an eight-point try, ruling there was "no foul play".

It mattered little as Chanel Mata'utia crossed for a second-half hat-trick, scoring in the 53rd, 59th and 79th minutes, Beau Scott charged over from Mullen's short pass to stroll over in the 64th, and Joey Leilua finished off another back-line raid in the 66th to contribute to the rout.

It completed a 72-point turn-around for the Knights, who were thrashed 48-6 by the Broncos in Brisbane seven days earlier.

Eels forward Ben Smith was reported for a "crusher" tackle on Chanel Mata'utia in the 78th but it did little to stop the 22-year-old winger, who beat Semi Radradra to recover Mullen's chip kick to score an acrobatic try a minute later to complete his treble.