Bayonne stormed to the French Top 14 summit with a stunning five-try 40-26 victory over champions Toulouse on Sunday.
Scores from Arthur Iturria, Baptiste Germain, Esteban Capilla, Cheikh Tiberghien and Tom Spring helped the Basques gain a measure of revenge for their Top 14 semifinal defeat to Toulouse last season.
Toulouse had led midway through the second half after tries from Matthis Lebel, Theo Ntamack and Georges-Henri Colombe, but despite bringing a string of France internationals off the bench, including lock Thibaud Flament and fly-half Thomas Ramos, they wilted in the final quarter.
And they paid for a wayward kicking performance from France fly-half Romain Ntamack, who missed two conversions and a penalty.
With top spot at stake, both teams came out firing in a lively opening.
Joris Segonds kicked Bayonne in front but moments later, Romain Ntamack's delightful chip kick gave Lebel the chance to acrobatically dive over in the corner.
Almost immediately, Bayonne were back up the other end and former England international Manu Tuilagi – who had a brilliant match – sucked in defenders before captain Arthur Iturria barged over from close range.
Segonds kicked another penalty but the Bayonne backline wilted under pressure just before the half-hour mark as hulking Toulouse No.8 Theo Ntamack – Romain's brother – ghosted through a gaping gap to score in the corner.
Incredibly, though, his brother, who had hit the post with his first conversion attempt, missed again.
In stark contrast, Segonds maintained his perfect record from the tee with a third successful penalty.
Centre Tuilagi was then yellow-carded for a cynical – and crunching – tackle on Theo Ntamack having failed to retreat 10 metres from a quickly taken penalty deep inside the Bayonne 22.
Romain Ntamack finally opened his account for the day, twice piercing the sticks to level the scores at 16-16 at the break.
TUILAGI DECISIVE
A third penalty from Ntamack at the start of the second period meant Tuilagi's sin-binning had been costly, turning a six-point lead into a three-point deficit for the Basques.
Bayonne almost responded immediately, but Australian No.8 Rob Leota's score after Toulouse spilt the restart was chalked off for a knock-on by winger Spring.
The champions' forward power and Bayonne indiscipline gave Ntamack another shot at the sticks but he missed for the third time.
Toulouse continued the uncharacteristic sloppiness when another spilt restart allowed Bayonne scrum-half Germain to score in the corner after good work from Tuilagi and flanker Capilla.
On the hour, replacement prop Colombe plunged over from close range and Ramos converted in front of the posts.
But a searing break from wing Arnaud Erbinartegaray set up Capilla to score and Segonds converted to give Bayonne a 28-26 lead with 10 minutes to play.
There was no Toulouse response as Bayonne ran away with it.
A typically barrelling run from Tuilagi set up the field position for Segonds to loft a long pass out to replacement full-back Tiberghien to barge through two tacklers and stretch out to score.
And Spring finished off a sweeping move in the final minute to leave the champions stunned.
