Depleted European Champions Cup holders Saracens were roundly beaten 30-10 by an upbeat Racing 92, who ripped open their visitors with four tries at the Paris La Defense Arena on Sunday.
Saracens made the trip to Paris without seven English internationals as they looked for an upturn in fortunes after a horrible fortnight.
They dropped an appeal against a £5.4 million ($6.97 million) fine and a 35-point English Premiership penalty for salary cap breaches earlier on Sunday, according to British media reports.
The points deduction will come into effect on Monday and the European champions could be forgiven for succumbing to a concerted French effort in Paris.
“The outcome of today’s game was never going to change the individual plans for those England players,” said Saracens director of rugby Mark McCall.
“We won’t play them when they’re not ready.”
The defeat is doubly damaging for Saracens as Pool 4 also includes a strong Munster side, who won 32-13 at Ospreys on Saturday.
“Winning our first game of the campaign against the defending champions was great,” said Racing scrum-half Maxime Machenaud, who made two conversions and scored two penalties. “Next week at Munster will be another story, but we took care of our side of the deal tonight.”
Virimi Vakatawa found space to run through the Saracens defence and place the ball between the posts for the first try on 10 minutes, with Frenchman Teddy Thomas extending the lead 16 minutes later.
Glimmer of hope
In the second half, Finn Russell rounded off a brilliant move before Wenceslas Lauret burst out of a scrum to force himself over the line for a try that assured a precious bonus point for Racing in what promises to be a tight group.
For Saracens, Alex Lozowski gave a brief glimmer of hope with the slickest try of the day after an interception and exchange of passes brought them to within eight points of the French on 51 minutes.
Earlier, French Top 14 leaders Lyon came crashing down to earth at Franklin’s Gardens as they slipped to a 25-14 defeat in their opening Pool 1 match against Northampton.
French spirits took a double dip as Montpellier were squeezed 23-20 by Connacht in their Pool 5 encounter in Galway.
Northampton, winners in 2000, opened up a 19-0 lead at half-time thanks to a converted Rory Hutchinson try and four penalties from Dan Biggar.
But in a fractious second half which saw the game interrupted on several occasions by outbreaks of fighting, Lyon began to show their worth with replacement centre Thibaut Regard crashing over twice.
Lyon were denied a defensive bonus point, however, by two further penalties from Biggar who finished with a personal haul of 20 points.
Montpellier took the early initiative against Connacht with former All Black Aaron Cruden going over for a try in the first minute.
The home side hit back with a penalty from Jack Carty and two tries just before half-time from flanker Paul Boyle and hooker Tom McCartney.
Trailing 13-10 at the break, Montpellier levelled through a Benoit Paillaugue penalty but Connacht soon pounced for their third try as scrum-half Caolin Blade darted through a gap close to the French line.
With 15 minutes remaining, Montpellier drew level again at 20-20, Anthony Bouthier getting the better of McCartney to sprint through, Paillaugue adding the extras.
Four minutes later replacement fly-half Conor Fitzgerald converted another penalty and Connacht clung on for the win.
The result means all four Irish provinces won on the opening weekend of the Champions Cup.