Top 14 leaders Clermont Auvergne were stunned by a thrilling Toulouse comeback as the division's top two shared a 20-20 draw.

Franck Azema's side boasted a 17-3 half-time lead but contrived to throw away that advantage as the spoils were shared at the Parc des Sports Marcel Michelin.

First-half tries from Apisai Naqalevu and Peter Betham helped put the hosts into a commanding position at the break.

But a Greig Laidlaw penalty was all they had to show for their second-half efforts, as Matthis Lebel and Romain Ntamack touched down for Ugo Mola's men.

It was left to Thomas Ramos to kick a last-gasp penalty to earn a memorable draw for Toulouse, but their celebrations were somewhat dampened by a serious-looking leg injury for Selevasio Tolofua.

In the other game of the day, Bordeaux-Begles overcame the first-half dismissal of Mahamadou Diaby to beat reigning champions Castres 32-13 and climb to fifth.

It represents a second consecutive home loss for Castres in the competition, after they fell to defeat against Agen at the start of the month.