In 2004, Stade Français successfully defending their title as the champions of France, defeating USA Perpignan in the final. Marconnet played in all of France's matches at the 2004 Six Nations Championship, as well as playing a further three tests in November of that year. In 2005, Stade Français played in the final of the 2004–05 Heineken Cup, which they lost to Stade Toulousain, the team were also finalists in the Top 14 final, which Biarritz Olympique won. He was capped 12 times for France that year, playing in the 2005 Six Nations Championship, as well as mid-year tests and end of year tests. He played the first match against Scotland in the 2006 Six Nations Championship, and was used as a replacement in the following matches against Ireland and Italy and was then called up for the subsequent game against England. On 4 February 2007, in the opening match of the 2007 Six Nations against Italy, he earned his 69th cap for the national team, thus becoming the most capped French prop, ahead of Christian Califano. He went on to play the two following matches against Ireland and Wales but broke his left tibia while skiing on 4 March. This injury sustained skiing kept Marconnet out of the 2007 Rugby World Cup in his homeland of France.