Toulouse claimed a hard-fought 21-11 win over Saracens at Stade Ernest-Wallon.
This match was hailed as the game of the weekend, and it certainly lived up to its billing in terms of entertainment and engrossing physicality, though tries were at a premium.
Toulouse's dominance at the breakdown and in the collisions was integral to their success; though they will no doubt be disappointed their ascendancy did not translate to a greater margin of victory.
In other matches on Sunday, Leinster fought back from 14-0 down to beat Castres 29-22 at Stade Pierre Antoine, while the Northampton Saints kept their play-off hopes alive with a 29-17 win against the Ospreys at the Liberty Stadium.
Ulster 27 Montpellier 16
Racing Métro 13 Scarlets 19
Harlequins 13 Clermont 16
Benetton Treviso 19 Leicester Tigers 34
Exeter Chiefs 10 Glasgow Warriors 15
Toulon 43 Cardiff Blues 20
Connacht 20 Zebre 3
Edinburgh 27 Perpignan 16
Gloucester 7 Munster 20
Castres 22 Leinster 29
Ospreys 17 Northampton Saints 29
Toulouse 21 Saracens 11