Toulouse collapse at Castres as Clermont suffer more misery
Toulouse missed the chance to join Montpellier at the Top 14 summit as they fell apart in a 28-23 defeat at Castres.
With the leaders and fellow top-four sides Racing 92 and Toulon not in action until Sunday, Toulouse had the chance to gain ground on their nearest rivals, but instead threw away a 23-8 half-time lead.
Castres has been thumped by Montpellier last time out and it looked like a similar story when early converted tries from Gael Fickou and Yoann Huget saw Toulouse seize the advantage at Stade Pierre Antoine.
A trio of penalties from Thomas Ramos ensured the visitors had a comfortable lead at the break, but Julien Dumora - who had already crossed in the first half - scored again early in the second to shift the momentum.
The deficit was reduced to one just before the hour mark when Alex Tulou touched down for Castres and Benjamin Urdapilleta converted.
A stunned Toulouse then had no answer when penalties from Urdapilleta and Rory Kockott completed the comeback to leave them third in the table, five points adrift of Montpellier.
Defending champions Clermont Auvergne's miserable campaign continued as they were thrashed 50-13 by Stade Francais.
Waisea Nayacalevu scored two of the hosts' five tries and Julies Plisson contributed 23 points with his boot as Clermont, who lost 49-0 to Toulon in their last league outing before falling to Racing 92 in the European Champions Cup, collapsed in the second half without scoring a point.
A late try from Baptiste Couilloud - and a key conversion by Lionel Beauxis - completed a dramatic comeback for Lyon in a 27-25 win at Brive to become the only away team to triumph on Saturday.
Brive were 12 points in front with 15 minutes remaining, but Liam Gill's converted try gave the visitors hope before Couilloud's late heroics as the hosts fell to their eighth loss in nine games.
Elsewhere, Bordeaux-Begles edged out top-six hopefuls Pau 19-18 courtesy of Baptiste Serin's late penalty, while Agen ran in five tries in a comfortable 36-21 home win over rock-bottom Oyonnax.