An under-strength Toulon returned to the Top 14 summit Saturday with a six-try, 44-15 win over Brive as defending champions Stade Francais and Racing 92 both slumped to shock home defeats.
European champions Toulon leapfrogged Racing to get to 51 points, two clear of the Paris side who were defeated 13-9 by Castres in what was their first home loss since May.
Stade, meanwhile, went down 33-18 to Grenoble who ran in three tries in the last 15 minutes.
Toulon had five players away on international duty in the Six Nations and were also missing winger James O’Connor, struck down by a mystery illness after last week’s win over Oyonnax.
But it was the home side who forged ahead with a penalty after five minutes and a penalty try four minutes later for a 10-0 lead.
Brive kept it tight to near half-time at 15-10 in wet, windy conditions with a try in the corner from Fiji winger Benito Masilevu after 19 minutes.
But on the stroke of the break, the Brive defence failed to deal with an up-and-under into their own try zone and Delon Armitage took full advantage by pouncing on a loose ball to touch down for 22-10.
Tries from lock Romain Taofifenua after 50 minutes and Kiwi fly-half Tom Taylor five minutes later put Toulon 39-10 up and ensured an offensive bonus point for the home side.
The hosts then completed the job with a sixth try five minutes from time, Drew Mitchell collecting a long crossfield kick from fellow Aussie Quade Cooper to barge his way over.
After the game, Toulon coach Bernard Laporte played down speculation that Australian international back O’Connor had been laid low by a heart problem.
“He has an illness. I will not use the words ‘heart problem’ because I am not a doctor and I don’t know that,” said Laporte.
“What is certain is that the battery of tests that he underwent were all good. Apparently it is nothing genetic or of the heart. I hope that he will be able to return as soon as possible.”
Racing 92, with All Blacks superstar Dan Carter playing at centre, lost their first home game of the season as 2013 champions Castres edged a 13-9 win.
Carter kicked all of Racing’s points but a try on the half-hour mark from winger Julien Caminati allowed Castres to celebrate their first home and away double over the Paris giants since 1999.
Castres had won 34-8 at home in November.
Stade, missing seven players away on Six Nations international duty, suffered their third home loss of the season to a Grenoble side who ran in four tries at the Stade Jean-Bouin.
The champions had led 18-16 at one stage thanks to tries in either half from Julien Arias and Laurent Panis.
But Grenoble fired back with two tries from hooker Arnaud Heguy in the space of six second-half minutes and New Zealand back-row forward Rory Grice in the dying moments.
The defeat left Stade 11 points away from the play-off spots.
Clermont are in third place after a bonus point, four-try 44-16 win over Oyonnax as they put an end to a run of three home losses.
Former French international scrum-half Morgan Parra kicked 22 of Clermont’s points.