|Nallet was named man of the match after his two tries at the Stade de France [GALLO/GETTY]
England won the Six Nations despite their defeat to Ireland when France beat championship challengers Wales in Paris.
Lionel Nallet twice charged over as France bounced back from their embarrassing defeat in Italy to beat Wales 28-9 at the Stade de France.
France end up in second place with six points, two behind England, who missed out on the Grand Slam when they slumped to a 24-8 defeat in Ireland earlier on Saturday.
Wales, who needed a massive win at the Stade de France to win the championship, finished fourth behind Ireland on points difference after both teams won three games.
Marc Lievremont, who accused his players of treason after the Rome debacle, now has something to cheer about less than six months before the World Cup after his team produced a solid performance.
Flankers Julien Bonnaire and Thierry Dusautoir were impressive, tackling tirelessly as France showed improvement in defence.
Wales were the first in action, with James Hook converting a very early penalty following a French offside.
France's bulky pack came inches from the visitors' line and, after Paul James was penalised for not rolling away from the tackle, Morgan Parra levelled with a routine strike.
Parra made it 6-3 as France dominated a game that started with a five-minute delay because French foreign minister Alain Juppe commented on the Libya crisis on France 2, the championship's official broadcaster.
Francois Trinh-Duc then saved a certain try when he ankle-tapped Leigh Halfpenny as the winger burst through.
Nallet then picked up a loose ball some 30 metres from the line and went over after selling the Wales defence a dummy as France reached the interval with an eight-point lead.
Hook sent another penalty over after the break but Nallet then took centre stage as he seized on second row partner Julien Pierre's charge down of Hook's clearance kick.
Parra and Hook traded penalties before the Welsh fly half picked up a harsh yellow card for a dangerous tackle.
Lievremont's side took full advantage of their superiority when a brilliant chip by Trinh-Duc ended in Vincent Clerc's arms for the winger to score his 24th international try.
Wales winger George North, 18, showed glimpses of his talent with a dazzling run through the French half before handing the ball to his supporting numbers – only for the move to end just short of the line.
"I'm very happy, we did what we had to do for the victory today," Nallet told the BBC.
Wales had travelled without assistant coach Shaun Edwards, who was reportedly involved in a bust-up with another backroom man after the Ireland game.
"It's an internal matter," said Gatland.