Newcastle Knights v Mounties
McDonald Jones Stadium
Friday, 3 August 3.45pm
After coming close against 11th-placed Wentworthville in a bottom-of-the-table showdown, the challenge increases tenfold this weekend when Newcastle host Mounties, who currently sit in second.
The Knights are now certain to get the wooden spoon in 2018 - they sit three wins behind the Magpies with a significantly worse points differential - while Mounties will need a miracle snag the minor premiership. While both teams' polar-opposite final standings are near certain, however, the Round 21 combatants will both be hopeful to put in a good performance in a rare Friday afternoon fixture.
Unfortunately for the home side, they will undoubtedly carry memories of a disaster in the teams' last meeting: a 62-0 thrashing in Round 13. They will need to try and put the heaviest defeat of the season behind them, as well as making do without regular five-eighth Jack Cogger.
St George Illawarra Dragons v Canterbury-Bankstown Bulldogs
Saturday, 4 August 12.45pm
Broadcast live on Fox League
Their last meeting ended in a one-point thriller at Belmore Sports Ground - and with the Dragons and the Bulldogs neck-and-neck in the race for a spot in the Intrust Super Premiership top four, it's all on the line at WIN Stadium.
Just nine points differential separate Canterbury-Bankstown (4th) and St George Illawarra (5th), meaning the game could go a long way to deciding which team earns the significant benefit of a top-four finish. Given the result in Round 10 - which saw the Bulldogs race to an 18-0 lead, before three Dragons tries, a Darren Nicholls penalty and field goal sunk the home side - Steve Georgallis's men will be on high alert this time around.
The Bulldogs have been in better recent form, with their three consecutive wins comparing favourably to the Dragons' one success from as many outings, but either side can, on their day, display their premiership credentials. The return of Jackson Ford highlights the changes to the Dragons side, while the Bulldogs will field a similar side to their Round 20 outfit - the NRL-bound Chris Smith is the notable exception.
Near identical in both points scored and points conceded this year, the teams will take part in a match which is nothing short of a blockbuster.
North Sydney Bears v Wyong Roos
North Sydney Oval
Saturday, 4 August 1pm
Broadcast live on Channel Nine and 9Now
With two lower-placed teams defeating competition heavyweights in Round 20, both could now be on the cusp of finals contention - but there may not be room for both.
It's a favourable position for the Wyong Roos, who have risen into the top eight after a start to the season which brought them just five competition points - a draw and two single-point victories. The Bears, sitting in 10th place, are not out of the race yet, but must at least win the majority of their remaining four matches.
Three experienced campaigners return to the North Sydney fold in the shape of Kyle Turner, Matt McIlwrick and Curtis Johnston, with the trio absent from the Bears' shock Round 20 defeat of Mounties. That win will fill the squad with confidence that they can not only make the finals, but overcome the top teams once they get there.
The Roos, too, got the better of a strong Dragons side at Allianz Stadium on Sunday and have named the same 17 - a rarity in the Intrust Super Premiership - for this weekend's clash. It will allow them to build momentum against a Bears outfit which should not be taken lightly.
Newtown Jets v Blacktown Workers Sea Eagles
Saturday, 4 August 3pm
Both Newtown and Blacktown will take positives out of their Round 20 matches, but the two competition points eluded either side - and now they both have work to do.
The Jets will need to put a heart-breaking Round 20 defeat to the Panthers behind them, which saw their last (albeit slim) chance of a minor premiership finish slipping through their fingers. A late surge for the table-topping Panthers earned them the victory, despite a generally impressive performance from the third-placed Jets.
In the Sea Eagles' case, a see-sawing affair finished in a similar six-point defeat to the Western Suburbs Magpies, but the consequences for Steve Hales' men could be more dire. They remain in ninth place for the third consecutive week, while a win would have returned them to the top eight. While it's not yet a must-win scenario for Blacktown, it's incredibly important if they are to feature in five weeks' time.
Penrith Panthers v Western Suburbs Magpies
Sunday, 5 August 1.45pm
Two early-season heavyweights will wrap up Round 21 on Sunday - but differences in recent form has seen the pair drift on the ladder.
While Western Suburbs have won one of their past four matches, the Panthers are undefeated for eight - which includes a 16-all draw in Round 13. It puts the defending premiers in pole position and highly likely to claim the minor premiership, meaning they are deserved competition favourites again.
The Magpies will need to lift to take down the Guy Missio-coached side, which they are sure to do in a Western derby at the foot of the mountains. Brett Hodgon's men have just one change to the 17 which took down Blacktown in Round 20 - Thomas Mikaele replaces Kurt Aldridge on the bench - while the Panthers welcome back the likes of Kaide Ellis, Reed Izzard and Liam Coleman.