England wing Henry Arundell marked his Top 14 debut with a hat-trick of tries but it was not enough to prevent Racing 92 from slipping to a 31-26 defeat at Toulon on Sunday.
Arundell, 21, who scored a joint England record five tries on his World Cup debut against Chile in September, touched down for the first time in the 36th minute, the sole consolation for Racing as they trailed 23-7 at half-time.
Setareki Tuicuvu extended Toulon's lead early in the second half, a fourth try for home side to add to first half touchdowns from Komiti Junior Alainuuese, Baptiste Serin and Gael Drean.
Noah Lolesio's penalty made it 31-7 on the hour but immediately Racing started a thrilling comeback with three tries in the space of 10 minutes.
Former London Irish flyer Arundell crossed twice with prop Thomas Laclayat also crashing over.
Toulon, however, clung on to secure just their second win of the season.
Racing collected a defensive bonus point, slipping to third in the table, three points behind Paris rivals Stade Francais, who won away at Lyon on Saturday, and Pau who both have 22 points.
As sides welcomed back more of their World Cup stars, champions Toulouse beat bottom side Perpignan 43-34 while Champions Cup winners La Rochelle ended a run of three successive defeats with an 18-15 win over Bayonne.