Fiji centre Sireli Maqala scored his sixth try of the season as Bayonne beat Racing 92 32-15 at home in the French Top 14 on Saturday.
Maqala’s second-half effort places him at the summit of the scoring charts for the season as the Basques sit seventh in the table.
They were denied an attacking bonus point, however, as Racing scored twice in the final 15 minutes.
“The end of the second half is annoying,” Bayonne back-rower Baptiste Heguy told reporters.
“We know every point is important, and there we let one go far too easily.”
Racing, without the rested ex-England captain Owen Farrell, suffered their fourth defeat of the campaign and languish in 10th.
“It’s difficult because we went out onto the field without conviction,” Racing forward Cameron Woki said.
“Unfortunately there were too few players who were hungry.”
Bayonne led 13-3 at the break as veteran Argentina hooker Facundo Bosch scored a try and fly-half Joris Segonds slotted a conversion and two penalties.
The hosts’ only score of the first half was a Nolann Le Garrec penalty, with the scrum-half expected to be named in France’s November Tests squad next week.
Maqala’s contribution came after 45 minutes as he stretched to dot down before Argentina winger Mateo Carreras and Bosch’s replacement Lucas Martin put the home side 32-3 up with a quarter of an hour to play.
The only negative for Maqala’s outfit was their inability to hold onto the attacking bonus point.
Fly-half Dan Lancaster, the son of Racing’s director of rugby Stuart, and scrum-half Clovis Le Bail’s late tries denied Bayonne the extra point.
Bayonne’s uncapped Tongan-born prop Tevita Tatafu came through the game unscathed before a possible inclusion in Fabien Galthie’s France squad for next month’s fixtures.
The 24-year-old Maqala’s good form is also good news for Fiji before they face Scotland, Wales, Ireland and Spain in November.
Later in the French first division, Toulon winger Jiuta Wainiqolo replicated compatriot Maqala as he also crossed but with a superb 50m solo effort as they beat Montpellier 30-17.
Another Fijian in Adrea Cocagi, who unlike Maqala and Wainiqolo has been omitted from their November Tests squad, was sent off for a high elbow as Castres eased past struggling Stade Francais 35-13.
Italy’s Tommaso Allan kicked 19 points as Perpignan held on to edge Lyon 29-26, days after the Azzurri announced the fly-half would return to the squad next month after missing games this season due to family reasons.
In the final game of the day, France captain Antoine Dupont provided two assists as record 23-time winners Toulouse beat Pau 22-14 to move top of the table.
Last weekend, the scrum-half scored a nine-minute hat-trick in his first game since claiming an Olympic rugby sevens gold medal.
On Sunday, second-placed Bordeaux-Begles can go back above Toulouse as they take a much-changed side and just one back on the bench to La Rochelle.