Racing start title defence with loss
Racing start title defence with lossSHARE
At the same time Clermont had to settle for a 30-30 draw at La Rochelle at the weekend.
Racing, who also reached the final of the European Champions Cup last term where they lost to English outfit Saracens, were edged out by a gritty Bordeaux performance in a match in which no tries were scored.
Ireland fly-half Ian Madigan kicked two early penalties on his debut after a close-season move from Leinster to put the hosts ahead, but his opposite number Dan Carter responded shortly before half-time to pull Racing to within three points.
Madigan slotted over another kick early in the second period, and although three-time World Player of the Year Carter hit back again, further Racing indiscipline allowed Madigan to add a fourth penalty.
Carter's trusty left boot gave Raphael Ibanez's visitors hope, but Madigan responded once more to put the game out of the champions' reach.
The capital side is the first team since Castres in 2013 to begin their Top 14 title defence with a defeat.
Clermont finished top of the regular season table last term before a controversial extra-time loss to Racing in the semi-finals, but they were denied a winning start to this campaign by a last-gasp penalty from Brock James.
Australian James played 289 times for Clermont in a 10-year stay at the club before joining La Rochelle for this season.
Noa Nakaitaci, Arthur Iturria and David Strettle all crossed in the first half to put Clermont 23-17 ahead at the break.
La Rochelle scrum-half Ricky Januarie added to earlier tries from Gabriel Lacroix and Uini Atonio before a James penalty gave the hosts the lead with quarter of an hour to play.
Two penalties from Morgan Parra took his tally for the game to 15 points and gave Clermont a slender advantage to hold on to in the final stages, but James held his nerve from the tee in the 77th minute to deny his former team-mates.
Elsewhere, 2015 champions Stade Francais began their bid to put a disastrous 2015/16 season behind them by thrashing Grenoble 54-20 at the Stade Jean-Bouin.
Stade ran in five tries, while Jules Plisson kicked 29 points in an excellent display.
Paul Williams touched down inside the first five minutes to get the ball rolling for the home team, before Remi Bonfils, Clement Daguin, Hugh Pyle and Waisea Nayacalevu scored in the second 40 minutes.
Toulouse also started their campaign well with a 20-12 home win over Montpellier, while Castres brushed aside Pau 28-11 and newly-promoted Lyon drew 15-15 with Brive.
Top 14 results:
Bordeaux-Begles 15 Racing 92 9
Castres 28 Pau 11
La Rochelle 30 Clermont 30
Lyon 15 Brive 15
Stade Francais 54 Grenoble 20
Toulouse 20 Montpellier 12
Bayonne v Toulon (16.15 GMT)