The battle to avoid the wooden spoon has been blown wide open after Cronulla and Newcastle shocked second-placed Penrith and defending premiers the Roosters respectively this round.

Just days after Knights coach Wayne Bennett announced he is leaving and star fullback Darius Boyd checked into rehab for depression, Newcastle stunned the Roosters 16-12 on Friday.

The Sharks also put their off-field turmoil aside to beat Penrith 18-16 at Bathurst on Saturday, drawing level with Canberra in equal last.

The blowtorch is on the Raiders to respond against the Rabbitohs at Canberra Stadium as they seek to avoid finishing bottom for the first time since their inaugural campaign in 1982.

He recently moonlighted as comic-book hero the Hulk for a jersey promotion, but Vaughan wants his teammates to fire up against the fourth-placed Rabbitohs as they look for just their sixth win of the year.

"There's still a lot of motivation for me,"  Vaughan said. "The boys are still going to be busting their arses each week, we may not be able to make the eight but we're not going to go into games half-hearted.

"I watched that [Newcastle] game. The comp at the moment is very tight and it shows any team can beat any of the top teams on their day.''

Canberra's 30-18 round-four upset over Souths in Sydney has been their best performance of the year, but also the most infuriating. They dominated from the outset to take a 22-0 half-time lead, and overcame the early loss to injury of back-rowers Shaun Fensom and Joel Edwards to hold on.

Further injuries, particularly to outside backs, have not helped, but the Raiders have won just three games since.

"It is a bit frustrating, but that's footy,'' Vaughan said. "It was certainly up there [as our best win]. We've got that in us and hopefully we can bring that out Monday night.''

Vaughan said the result had given Canberra's pack belief they could hold their own against one of the NRL's best, led by the Burgess brothers.

"One of the strongest points in our game is the middle, we don't get dominated too often and we're always fairly strong,'' Vaughan said. "Sam and George [Burgess] are obviously the pick of the brothers and there's always a couple of boys in each side you want to test yourself against. We beat them up there on their home ground, I'm sure they'll want to come down here and get the wood on us.''

One of the highlights promises to be the fullback battle between Raider Anthony Milford and Greg Inglis, who he spent some time with in Queensland Origin camp this year.

The Raiders will be keen to ensure in-form centre Jarrod Croker receives more chances after the NRL's second-leading try-scorer was starved of the ball in last week's loss in Melbourne.

Former Raider Joe Picker may also make his first appearance at Canberra Stadium since he was offloaded by the club at the end of last year. The back-rower was named on an extended six-man Souths bench this week, but is a chance to play after he did not feature for NSW Cup affiliate North Sydney on Saturday.

"It's a bit funny seeing 'Joey' running around with the stripes on, he's still a Raider for me,'' Canberra halfback Josh McCrone said. "He's one of my best mates and it was sad to see him go, that's just the nature of the business really.''

MONDAY

NRL round 20: Canberra Raiders v South Sydney Rabbitohs at Canberra Stadium, 7pm. Tickets available from Ticketek. TV time: Live on Fox Sports 1

RACE TO AVOID THE SPOON

13th: Gold Coast Titans 20 points, -66 points differential

14th: Newcastle Knights 16 points, -94 points differential

15th: Canberra Raiders 14 points, -117 points differential

16th: Cronulla Sharks 14 points, -186 points differential

THE RUN HOME

CANBERRA (15th, 14 pts, -117)

Rd 20: Souths (h)

Rd 21: NZ Warriors (h)

Rd 22: Parramatta (a)

Rd 23: St George Illawarra (h)

Rd 24: Cronulla (a)

Rd 25: Wests Tigers (h)

Rd 26: Parramatta (h)

CRONULLA (16th, 14pts, -186)

Rd 21: Parramatta (h)

Rd 22: Warriors (a)

Rd 23: Melbourne (a)

Rd 24: Canberra (h)

Rd 25: Wests Tigers (a)

Rd 26: North Qld (a)

NEWCASTLE (14th, 16 pts, -94)

Rd 21: Souths (a)

Rd 22: Melbourne (h)

Rd 23: NZ Warriors (h)

Rd 24: Brisbane (a)

Rd 25: Parramatta (h)

Rd 26: St George Illawarra (h)