Stand-in South Sydney coach Jason Demetriou filled the temporary void left by Wayne Bennett's breach of the NRL's COVID-19 protocols by orchestrating a 28-10 win over Brisbane.

In cold and wet conditions at Sydney's Olympic stadium, Demetriou took the reins with Bennett absent in the coaches' box as the Rabbitohs added another layer to the Broncos' miserable season, marred by 10 defeats in their past 11 matches.

The Rabbitohs had taken the field in Sydney's west not long after learning Bennett had been fined $20,000 for breaching the NRL's biosecurity guidelines he helped develop as a member of the Project Apollo committee.

Bennett was earlier banned for two weeks on Thursday after admitting to leaving the Rabbitohs' bubble.

The Broncos had also been sanctioned on Friday, with three members of their training staff, including club legend Allan Langer, fined $5,000 for attending a private function in Brisbane, also in direct breach of the NRL's strict rules.

The mood of the Broncos did not brighten in their grudge match against the Rabbitohs, with their darkest moments coming in defence as they conceded four tries.

The worst of it happened minutes before half-time when Rabbitohs replacement forward Mark Nicholls took a quick tap from 10 metres out and cruised through big men Payne Haas, Matt Lodge and Boyd to score.

Loading

It was woefully soft defence from the Broncos, who had been in the contest before the unforgivable lapse in concentration.

In contrast, it was a composed performance by the Rabbitohs, steered by halves Cody Walker and Adam Reynolds.

The Rabbitohs' tries were scored by Dane Gagai, Reynolds, Nicholls and Tom Burgess.

They move to provisional sixth position on the ladder on the back of their seventh win of the season.

Winger Herbie Farnworth and returning forward David Fifita crossed the stripe for the Broncos, who are placed second-last on the ladder.

The win would have been satisfying for Demetriou, who was a casualty of the coaching swap that saw Anthony Seibold replace Bennett at the Broncos in late 2018.

Demetriou, a Broncos assistant under Bennett at the time, interviewed for the job that was eventually given to former Rabbitohs coach Seibold.

He eventually followed Bennett to the Rabbitohs and is set to replace the seven-time premiership coach at Redfern as part of a succession plan at the end of the 2021 season.

The rivalry between the respective coaching staffs has only added to the heated feeling that has highlighted clashes between the Rabbitohs and Broncos in the past two seasons.

Manly goes down in upset loss to Warriors

Manly's finals hopes took a hit after falling short of completing a late comeback against the Warriors in its 26-22 loss at Brookvale Oval.

In a brutal night for the Sea Eagles, they lost both Martin Taupau (concussion) and Addin Fonua-Blake (lower-leg cork) during the match.

The Sea Eagles, who sit one spot outside the top eight, have now lost five of their past seven matches since Tom Trbojevic was sidelined with a hamstring injury in round six.

Trbojevic is still two weeks away from making his return, while teammate Dylan Walker is facing another five rounds on the sidelines.

In Des Hasler's 400th match as coach, it all went wrong for the Sea Eagles in a horror 18-minute opening where they conceded three tries and lost Fonua-Blake to injury.

Daly Cherry-Evans was again strong for Manly alongside Moses Suli, but not even the Kangaroos half-back could engineer a winning result after trailing 16-0 early.

The Warriors' win, meanwhile, marked the first time they have won back-to-back matches since last May and they sit just two wins out of the top eight.

Kodi Nikorima and Chanel Harris-Tavita both kicked superbly close to the line, with four of their five tries coming off the pair's boots.

Patrick Herbert bagged a double, with his first a diving effort to latch onto a Nikorima cross-field kick and score in the same motion.

But the Warriors' win was not without its dramas.

Prop Jack Hetherington faces a lengthy stint on the sideline for a high shot that left Taupau concussed.

He was sin-binned but lucky not to be sent off, in a moment that threatened to blow the match wide open.

Manly took full advantage of the extra man, when Cade Cust put a charging Haumole Olakau'atu over from close distance with 22 minutes to play.

The margin was then down to four points with 12 minutes to play when Tevita Funa put Jorge Taufua over, after Cherry-Evans opted to run it on the last.

AAP/ABC