Record 20-time champions Toulouse ran in seven tries in a 48-24 demolition of old rivals Stade Francais on Sunday to take pole position in the French Top 14.
It was Toulouse's 10th win of the season and sixth in a row and proved sweet revenge for their 48-14 mauling at the hands of Stade in November.
That setback was the last time Toulouse lost a game.
Winger Matthis Lebel scored two of Toulouse's tries with the 21-year-old now the tournament's leading scorer with eight.
Antoine Miquel, Antoine Dupont and Yoann Huget, with a brace, as well as a penalty try completed the scoring.
Stade, who are fifth in the championship, have not won at Toulouse since September 2006.
"We were spanked by them last time and we remembered that this week," said Lebel.
"It's good to be at the top of the championship today but the most important thing is still to be first at the end."
Toulouse were also helped into first spot when previous leaders La Rochelle had their game at Racing 92 called off due to a positive Covid-19 test at the club.
Toulon's home game with Bayonne, scheduled for Friday, was also postponed.
The French government, meanwhile, has even recommended clubs postpone upcoming European Cup matches with British teams due to the new Covid-19 variant.
The decision casts a doubt over the final two rounds of pool matches scheduled to start next weekend.
A meeting to discuss this year's Six Nations, set to begin on February 6, will also take place in the coming days.
Former France coach Philippe Saint-Andre said it was a blow to the squad's morale to lose his second game in charge of strugglers Montpellier, a last-gasp 23-22 defeat at Brive, despite having enjoyed a 19-0 half-time lead.
Saint-Andre, who took over from the sacked Xavier Garbajosa last weekend, also tasted defeat on Wednesday at Lyon.
"We played well for the first half. If we want to stay in the Top 14 we have to play well for 80 minutes," Saint-Andre said.
"For the morale, it's difficult, the players gave a lot," he added.
Montpellier led comfortably at the break as France's Arthur Vincent and Anthony Bouthier, deputising at flyhalf for South Africa's Handre Pollard who has been out since September with a serious knee injury, were on the scoresheet.
The pair are set to be named in France's Six Nations squad on Monday along with team-mates Paul Willemse and Mohammed Hoauas.
Prop Haouas, who will be questioned on 29 January for an alleged robbery of a tobacconist, was shown a yellow card for a high tackle after two minutes of the second half.
Brive snatched victory in the last minute when hooker Thomas Acquier muscled his way over for a converted try.
Saint-Andre's men remain in the relegation playoff spot and are winless in six games as Brive move up to ninth.
Argentina winger Bautista Delguy claimed a double as Bordeaux-Begles overcame Lyon 31-9 and Clermont beat Pau 42-31.
On Saturday, Fiji sevens international Vilimoni Botitu claimed his first Top 14 try in Castres' 39-23 home victory over Agen to extend the bottom side's winless run to 14 matches.
French Top 14 results:
Brive 23-22 Montpellier
Pau 31-42 Clermont 42
Bordeaux-Begles 31-9 Lyon
Toulouse 48-24 Stade Francais
Racing 92 v La Rochelle - postponed
Castres 39-23 Agen 23
Toulon v Bayonne - postponed