He played in the final of the 2005–06 Heineken Cup at Millennium Stadium in Cardiff, which Biarritz lost to Irish team Munster 23–19.

He played in the subsequent match against the Springboks at Newlands Stadium in Cape Town with France again emerging as the victors.

His second-half score helped France to a 20–18 victory over the tournament favourites, despite the fact that he was not in the original 30-man squad and was only called up as a replacement for the injured Elvis Vermeulen.

[citation needed] Dusautoir captained France to the 2011 Rugby World Cup final against the hosts New Zealand, in which he scored France's only try (one of two for the entire game) in the 47th minute (New Zealand's Tony Woodcock scoring the other for the All Blacks) and made 22 tackles, for which he received the Man of the Match award.

On the night of the final, one could hear chants of "Dusautoir" coming from the many bars showing the game around the Auckland waterfront.

[10][11][12] In an interview on Total Rugby in July 2012, Dusautoir spoke about a perceived lack of respect towards his team during the 2011 World Cup.

[13] Dusautoir also shared about how France's uncomplicated game plan in the final nearly resulted in a memorable upset: Our strategy in that match was to resist as long as possible.

But by this time we were sure we were mentally prepared and we were ready to make the most of the opportunity... During the match we played well but we would have liked to have scored a drop goal on top of the great defence we produced.

[15] Dusautoir lead France to the knockout rounds of the 2015 Rugby World Cup, where they played against New Zealand in the quarter-finals, losing 62–13.