South Africa's two-time Rugby World Cup winning captain Siya Kolisi watched from the stands as his new club Racing 92 beat Stade Francais 13-9 on Saturday in the French Top 14 but their local rivals remained in the number one spot.
Kolisi, 32, joined the side after lifting a second Webb Ellis trophy late last month and will make his debut for the Parisians next Sunday against La Rochelle.
The iconic Springbok followed the game alongside Chelsea captain Reece James, as the footballer benefitted from his free time during the international break to take in the match. The pair are represented by the same agency, Jay-Z's Roc Nation.
Racing's victory in rainy conditions had moved them above Stade Francais to top of the table based on their head-to-head record before Castres beat 31-23 Toulouse later in the day to go third and send Stade back top with all three sides tied on points after seven rounds.
"I've been involved in many big derbies internationally with England-Wales, England-France, or club level with Leinster-Munster, and it's right up there the feeling in the changing room," said Racing coach Stuart Lancaster.
"It wasn't perfect, but I felt all the big players stood up and played and we deserved it in the end," the former England and Leinster boss added.
Kolisi's new outfit led 10-6 at the break thanks to centre Henry Chavancy's try and four points from the boot of South African fly-half Tristan Tedder.
Stade Francais fly-half Joris Segonds made it a one-point game just after the interval with his third penalty of the match.
Racing, champions in 2016, held on for victory, an eighth straight at their rivals' Stade Jean-Bouin, as promising French scrum-half Nolann Le Garrec kicked a 54th-minute penalty.
- 'Inspiration' Jones -
Later, Test rugby's most capped player in former Wales and British and Irish Lions captain Alun Wyn Jones made the final appearance of his career as Toulon edged Clermont 30-27 for their first win at Stade Marcel-Michelin in eight years.
"We played for Alun Wyn Jones tonight, and this result doesn't surprise me, because we have players just like him: humble, hard-working," Toulon assistant coach Sergio Parisse said.
"He's a source of inspiration for our team," the ex-Italy skipper added.
Pau failed to leapfrog Racing losing 35-16 to Bayonne, a first defeat to the Basques since 2005.
Perpignan moved from bottom spot, beating Montpellier, who were 13th in the table, 23-16 thanks to English winger Ali Crossdale's acrobatic 71st minute try.
Montpellier president Mohed Altrad told newspaper Journal De Dimanche after the game he had appointed controversial former France head coach Bernard Laporte as director of rugby to help struggling head coach Richard Cockerill.
Laporte resigned from his position as French Rugby Federation president in January after being found guilty of favouritism in awarding a shirt sponsorship contract for the national side to Altrad, Montpellier's billionaire owner.
Later, France captain Antoine Dupont unusually started at fly-half as Toulouse lost at Castres as the hosts went up to third thanks to impressive performances from French playmaker Pierre Popelin and Australian lock Tom Staniforth.
On Sunday, Bordeaux-Begles visit double Champions Cup winners La Rochelle, who have tasted victory just twice this campaign.