Racing 92 prepared for next weekend's Champions Cup quarter-final with a 45-27 comeback hammering of Bordeaux-Begles in the French Top 14 on Sunday.
The Parisian side host four-time European champions Toulouse in the last eight of the continental competition next Sunday and scored more than 40 points at their La Defense Arena home for the sixth time this season in a fine bonus point win.
Brock James opened the scoring for the away side with a fifth-minute penalty kick before France forward Bernard Le Roux dotted down after nine minutes for the hosts.
Bordeaux-Begles responded well and took a commanding-looking 20-7 lead thanks to another James three-pointer and tries for Yann Lesgourgues and Nans Ducuing.
However Ireland second row Donnacha Ryan's 24th minute converted try brought the scores to 20-14 at the break, and Racing's comeback continued five minutes into the second half.
France hooker Camille Chat bundled over and Machenaud's conversion gave the hosts the lead for the first time since the 10th minute, and Georgia prop Vasil Kakovin then extended the advantage with his first try of the season.
Machenaud added another penalty and substitute back-rower Baris Palu dived over to bring the score to 38-20 with 15 minutes to play.
The Parisians played the final 12 minutes with 14 men after Machenaud's replacement Teddy Iribaren was sent off for punching Baptiste Serin.
Simon Zebo claimed his 13th try of the campaign in the closing seven minutes to take the home side over the 40 point-mark.
Fiji winger Semi Radradra crossed for a consolation score in the final minutes.
Racing move up to fourth place on 56 points, for ahead of Bordeaux who remain sixth after their fifth loss in nine matches.
Later on Sunday league leaders Toulouse travel to play off-chasing La Rochelle.