Paris - Bordeaux-Begles made history by becoming the new leaders of the Top 14 on Sunday while All Black wing Ben Smith was sent off on his Pau debut, but Springbok lock Eben Etzebeth was a star performer for Toulon.
Bordeaux beat the Victor Vito-led La Rochelle 20-15 in a derby match, scoring the decisive, and only, try of the game through Fijian Peni Ravai - thought to be the only prop to have played international sevens - eight minutes from time.
In front a crowd of more than 38 000 at Bordeaux's Matmut Atlantique stadium in wet, greasy conditions, Matthieu Jalibert kicked five penalties for the home side, while Jules Plisson booted five of his own for La Rochelle.
The result, allied with previous leader Lyon's 29-12 defeat by Castres on Saturday, saw Bordeaux move to the league's number one spot for the first time in the club's history.
"You could call that a perfect afternoon," waxed Bordeaux coach Christophe Urios.
"Last year, Bordeaux handed me the worst Christmas of my life by winning at Castres (where he was then coach). Now I'm going to have a very happy Christmas thanks to Bordeaux!"
South Africa's World Cup-winning lock Etzebeth marked his Top 14 debut with a fourth-minute intercept try that saw him charge home from 40 metres for the opening score in a comprehensive 41-19 victory over Clermont, the club's eighth straight win.
Etzebeth was omnipresent throughout and received a standing ovation when he was subbed off with 10 minutes to play.
A pinpoint Louis Carbonel kick-pass saw wing Bryce Heem cross for Toulon's second try, while Georgian prop Beka Gigashvili burrowed over shortly after.
Clermont saw prop Rabah Slimani yellow carded but responded with a try from Sipili Falatea before Toulon closed the first-half with a bonus-point fourth try from Raphael Lakafia.
Clermont's France winger Damien Penaud was first over the whitewash in the second period, before Toulon hit back through centre Julien Heriteau and a penalty try, the visitors having the final word with a third try through George Merrick.
The game kicked off with an announcement from controversial Toulon president Mourad Boudjellal that he would step down at the end of the season, bringing a close to a star-spangled period for the Mediterranean club.
"I've tried to change the destiny of this club and I hope something of that will remain," said Boudjellal, who financed a raft of high-profile signings including Jonny Wilkinson, Matt Giteau, Bryan Habana, Bakkies Botha and Carl Hayman as the team powered to three European titles.
In the day's early game, Pau winger Smith, capped 84 times by New Zealand, was shown a red card by international referee Alexandre Ruiz in the 51st minute for an elbow-led fend that left Stade Francais hooker Lucas Da Silva prone.
"We're a little sad for him," Pau coach Frederic Manca said of Smith, with the side eventually going down 21-18 to Top 14 strugglers Stade Francais.
"There was no intent to lift the elbow or plant it in the throat."
Pau took an early lead, Antoine Hastoy hitting two penalties either side of a Siegfried Fisi'ihoi try.
But the Parisians hit back with tries either side of half-time from Arthur Colville and Quentin Bethune, Joris Segonds converting one and adding three further penalties.
There was drama until the end, however, as Pau captain Lucas Rey crossed for a 72nd minute try, converted by Tom Taylor.
But bottom-placed Stade held on for just their third victory of the season, while Pau return home with the consolation of having picked up a losing bonus point.