Paris - France veteran Frederic Michalak kicked 10 points as surprise package Lyon went top of the French league with a 25-6 win at newly-promoted Agen on Saturday.
Lyon replaced Montpellier at the Top 14 summit after the latter lost 31-20 at Stade Francais, for whom irrepressible Fijian winger Waisea Nayacalevu scored a brace of first half tries.
Bordeaux-Begles moved up to third after hitting back from an 18-3 deficit to edge visitors Toulon 30-27.
Lyon outscored their hosts three tries to none to even secure the attacking bonus point that put them three points clear, as they look to emulate La Rochelle's stunning achievement from last season in topping the regular season standings.
Agen took an early 6-3 lead through two penalties from Australian flyhalf Jake McIntyre but tries from Thibault Regard and Jean-Marcelin Buttin had Lyon in command at half-time, leading 15-6.
Richard Choirat sealed the bonus point while 34-year-old Michalak knocked over two conversions and two penalties.
In Paris, Stade managed to continue their upward trajectory started with last week's win at Pau as Waisea proved the key mover against a Montpellier side missing the injured Aaron Cruden and Jannie du Plessis.
"It's an important victory for us after Pau," Stade backs coach Julien Dupuy said of a side that has lost two home matches.
"We suffered a bit at the start of the season, but that now makes us smile. It's a strong signal to others and ourselves: we have to stop looking at others, we're a good team."
Montpellier forwards coach Nathan Hines, the Australian-born ex-Scotland lock, warned of further losses "should we lose as much ball as we did today".
"We made too many mistakes and didn't play as we planned. We didn't master anything, everyone's frustrated."
A mispass from Stade playmaker Jules Plisson found Waisea alone on the wing after 10 minutes, and the rest was academic despite a good covering effort by Montpellier scrumhalf Ruan Pienaar.
Scrumhalf Arthur Coville was instrumental for the second try, launching a counter attack from the Parisian club's 22m area, his chip ahead gathered by Julien Arias who also grubbered through.
With the defence all at sea, Waisea was on hand to scoop up the ball and sprint to the line.
The Parisians then suffered a hammer blow when flanker Sekou Macalou was sin binned in 39th minute for failing to roll away in the tackle.
Montpellier's Bismarck du Plessis immediately crashed over from a driving maul, Pienaar converting to make it 20-10 at half-time.
And with Macalou still off the paddock early in the second period, giant Fijian winger Nemani Nadolo showed all his power to muscle in from close range after great interlinking play among the Montpellier backs.
No sooner had Macalou made it back onto the pitch than Montpellier suffered the same fate, with prop Antoine Guillamon binned for a scrum binding infringement.
Plisson's third and fourth penalties, followed by a second for Pienaar left it 26-20 with the final quarter to play.
Waisea turned provider for the third, decisive try, accelerating away down the wing and offloading inside to Arias, who in turn found Tony Ensor, the Kiwi fullback sliding over for the final word.
Bordeaux were in trouble with half-time approaching as tries from bullocking Fijian wing Josua Tuisova and South African lock Juandre Kruger helped Toulon pull clear early on.
But Jean-Baptiste Dubie started the fightback by crossing the whitewash four minutes from the break.
The wing got his second soon after Bordeaux were awarded a penalty try while New Zealander flyhalf Simon Hickey went over too as Bordeaux scored three tries in a blistering 11-minute period to streak into a 30-21 lead.
France fly-half Francois Trinh-Duc bagged two late penalties to snatch a defensive bonus point for the three-time European champions, but they dropped a place to fifth.
Brive finally got off the mark this season following five straight defeats as they beat Castres 27-22.
They remain bottom, though, a point behind Agen and two off Oyonnax, who lost 19-16 at home to Pau.