Joint-leaders Castres moved five points clear of champions Perpignan on Friday with a 34-6 win while Toulon edged Stade Français 22-18 in Paris.
Friday's other Top 14 fixture saw Racing Métro sneak a 9-6 win against basement side Albi to boost their own play-off aspirations.
Philippe Saint-André's outfit, however, are now five points above the giants from Paris and move into third position thanks largely to the form of Jonny Wilkinson, who kicked thirteen points on the night.
But what continues to be the big story of 2009/10 has to be the Tarnais' form at the right end of the table, with four points once again picked up, this time at home to a shell-shocked Biarritz.
Full wrap to follow on Saturday
Stade Français 18-22 Toulon
Castres 34-6 Biarritz
Racing Métro 9-6 Albi
Fixtures: Saturday, November 28
Toulouse v Montauban
Montpellier v Brive
Bayonne v Perpignan
Clermont v Bourgoin
1 Castres 46
2 Perpignan 41
3 Toulon 38
4 Toulouse 36
5 Clermont 36
6 Racing-Métro 35
7 Stade Français 33
8 Biarritz 32
9 Montpellier 29
10 Montauban 25
11 Brive 24
12 Bayonne 23
13 Bourgoin 23
14 Albi 15
Stade Français 18-22 RC Toulon
Stade Jean Bouin, Paris
With a whole host of internationals absent, it was in fact Stade who came out the stronger when Ollie Phillips opened the scoring with just two minutes on the clock.
But Toulon - boosted by the return of Jonny Wilkinson - were quickly closing the arrears thanks to his penalty before Noel Oelschig kicked six points to move the hosts 11-3 up.
Wilkinson was then on hand to drop a goal following wing Christian Loamanu's late first-half try to send the visitors in ahead as they looked to edge into the play-offs.
And that they did despite centre Mathieu Bastareaud's 53rd minute try with a further three Wilkinson penalties sealing the vital points in front of a disappointed Stade Jean Bouin.
Castres Olympique 34-6 Biarritz Olympique
Stade Pierre Antoine, Castres
Castres made light work of Biarritz on Friday to apply the pressure on an under-strength Perpignan, who take on Bayonne away from home this Saturday.
Romain Teulet was as reliable as ever for the hosts as he kicked 16 points in an assured team effort that had gloss added by Nicolas Matthieu, Yoan Audrin and Ibrahim Diarra.
Racing Métro 92 9-6 SCA Albi
Stade Yves Du Manoir - Colombes (Paris)
Racing-Métro 92 were made to work for their four points against the league's bottom side as veteran New Zealand fly-half Andrew Mehrtens kicked them up to sixth in the standings.
Blair Stewart's two penalties were Albi's only answer at Stade Yves Du Manoir but they left with just a losing bonus-point that does little to help their relegation-fighting cause.