Montpellier's late rally did not deny Top 14 leaders Clermont Auvergne a 28-23 victory, while Guilhem Guirado scored a try in Toulon's win.
Alex Allan's dismissal did not prove costly as Glasgow Warriors beat the Scarlets, while Leinster scored 59 in a victory over the Dragons.
Defending champions Saracens have won each of their opening nine Premiership fixtures as they stayed perfect by beating Wasps 29-6.
After Argentina and Barbarians scored five tries apiece at Twickenham, Elton Jantjies' late drop-goal settled a thrilling contest.