France kept alive their dreams of a first Grand Slam and Six Nations title since 2010 with a tense 13-9 win over Wales.
An Anthony Jelonch try and eight points from Melvyn Jaminet set up the victory.
Spirited Wales responded with three Dan Biggar penalties, but could not break down the French defence.
Fabien Galthie’s side will aim to complete the Grand Slam against England next Saturday in Paris, while Wales host Italy in their final game.
It was a third defeat in four matches for Wayne Pivac’s defending champions, alongside a narrow victory over Scotland.
Despite second-half territory and possession dominance, along with inspired performances by Biggar and Taulupe Faletau, Wales’ lacklustre attack could not crack a resolute French rearguard expertly organised by familiar face Shaun Edwards.
The France defence coach was part of Warren Gatland’s Wales backroom team between 2008 and 2019 - a period that delivered four Six Nations titles, three Grand Slams and a World Cup semi-final appearance - before he joined Galthie’s set-up.
The closest chance came when Wales centre Jonathan Davies just failed to hang onto a pass in the second half with the French line at his mercy.
Led by hooker and man-of-the-match Julian Marchand, France also excelled at the contact area as they took their winning sequence to seven games.
Their first Six Nations silverware in 12 years is now beckoning.
Friday night rugby was back for the first time in the Six Nations in Cardiff since 2017 with the Principality Stadium roof open.
The game was unusually played out in front of some empty seats, with 63,208 attending a stadium that holds 74,500.
Factors such as the game being held on Friday night and travel issues, Covid-19 concerns, Wales losing two out of their first three matches and ticket prices, some costing £100, all helped explain the 11,000 absent fans.
There had been talk of fewer French fans travelling, but that did not translate into the Principality Stadium cauldron with the thousands who had made the trip in fine voice.
Wales head coach Pivac made four changes with Cardiff duo Seb Davies, normally a lock, and Josh Navidi packing down in the back row instead of Ross Moriarty and Taine Basham.
Navidi demonstrated no rustiness despite having played only one game in five months since recovering from a shoulder injury.
Injured centre Nick Tompkins was replaced by Jonathan Davies, with prop Gareth Thomas preferred to Wyn Jones.
France made one change from the side that defeated Scotland as winger Gabin Villiere came in for Damian Penaud, who had tested positive for Covid-19.
Jaminet and Biggar exchanged early penalties before France showed their class with a flowing move for the only try, finished by flanker Jelonch following a scoring pass from Jaminet, who also converted.
(BBC Sports)