Clermont Auvergne took over as Top 14 leaders with a 46-27 win over Bayonne after La Rochelle failed to pick up a bonus point in their defeat of Stade Francais on Saturday.
La Rochelle stretched their magnificent winning run to eight games in all competition by seeing off Stade 37-18 in the first game of the day.
That victory at Stade Marcel-Deflandre put them five points clear of Clermont, but Franck Azema's men responded by blowing bottom side Bayonne away in the first half.
Bayonne simply had no answer to Clermont in the opening 40 minutes, with scrum-half Charlie Cassang helping himself to a double either side of an early try from Aurelien Rougerie and Damian Penaud's score.
Stephen Brett also booted nine points as Clermont opened up a 29-0 advantage at the break, but Bayonne showed character to score 20 points without reply – including a penalty try and another from Pablo Huete – to make a game of it.
Clermont were not to be denied the bonus-point win they needed to take top spot, as Judicael Cancoriet and Alexandre Lapandry touched down to give them breathing space.
Victor Vito scored an early try, while replacements Jules Le Bail and Levani Botia crossed in the second half as La Rochelle's long winning streak continued. Brock James racked up 22 points from the tee for the hosts, who show no signs of falling off the pace.
Bryan Habana was among the try-scorers in Toulon's 31-17 win over Lyon, while Pau beat Grenoble 39-22 and Leone Nakarawa scored two second-half tries in Racing 92's 33-25 home win over Brive.