Melbourne Storm handed Newcastle Knights their first loss of the 2020 NRL season, while Latrell Mitchell's fine first half led South Sydney Rabbitohs to victory against Gold Coast Titans.

The Storm's 26-12 success against the Knights at Central Coast Stadium means leaders Parramatta Eels are the only remaining undefeated team in NRL this year.

Ryley Jacks went over after just three minutes before Cameron Smith set up first-half tries for Suliasi Vunivalu and Tino Faasuamaleaui - his first in the competition - to send Melbourne into the interval with a commanding 18-2 lead, but the Knights responded well with Bradman Best and Edrick Lee making it a one-score game.

However, Cameron Smith slotted through a penalty after David Klemmer was pinged for an early tackle and Brandon Smith somehow barrelled through three defenders with three minutes remaining to clinch the victory.

In Saturday's first game, the Rabbitohs were 32-12 winners over the Titans at Bankwest Stadium thanks in large part to Mitchell.

The former Sydney Roosters full-back caught the ball and dotted down in the third minute after Damien Cook's pass bounced off his chest to get Souths up and running.

Phillip Sami briefly restored parity before Alex Johnston crossed to restore the Rabbitohs' lead. Mitchell then tipped a pass to Dane Gagai to race in at the corner and saw Anthony Don's failure to gather his grubber kick enable Braidon Burns to put the Bunnies well on top.

The Titans were unable to gain momentum despite Bryce Cartwright's 44th-minute score, with Gagai's second try followed by a conversion from Adam Reynolds, who finished the game with 12 points.

Canberra Raiders got back to winning ways by coming from behind to defeat Wests Tigers 14-6 in Ricky Stuart's 400th game as an NRL coach.

The Raiders were trailing to Luke Brooks' uncovered first-half score, but Jack Wighton's try five minutes following the restart was converted by Jarrod Croker and Nick Cotric dived over after Russell Packer was sent to the sin bin for a professional foul on Jordan Rapana just five minutes after coming on.

Moses Mbye reduced the deficit from the tee but, after Packer was placed on report for a high tackle upon his return, Croker restored Canberra's eight-point cushion as they moved up to second.