[4] In 2001, Paulissen became an elite professional rider by officially signing an exclusive, two-year sponsorship contract with Italy's Rainer Wurz MTB Team, and then capped off his season by mounting four top-ten finishes at the UCI World Cup series.

[7][8] In that same year, Paulissen managed to earn another triumph on the second stage of the UCI World Cup series in Houffalize, and eventually edged out his teammate Meirhaeghe to take home the overall silver medal in the final round of the circuit.

[citation needed] Paulissen started his 2008 season by defending the men's cross-country race title at the Belgian Championships and by taking part in the Roc d'Azur MTB Marathon tournament, where he registered two more triumphs in the process.

Being the first man up after hitting the tarmac hard, Paulissen reluctantly carried his broken bike towards the finish, while his rival Sauser remounted his lead to cross the line first, but ended his campaign with a protest.

[17][18][19] Paulissen started the 2009 season by claiming his tenth Belgian national championship title, and by signing an exclusive, two-year sponsorship contract with Germany's Cannondale Factory Racing pro team.

[20] He also defended his men's marathon race title and rainbow jersey at the UCI World Championships in Graz, Austria with a time of 4:34:46, edging out the home nation's Alban Lakata on another tight, sprinted duel match by fifty-one seconds.

Moreover, he ordered a two-year suspension from the Union Cycliste Internationale (UCI) for failing the doping test, missing a chance to defend his Belgian national championship title and pursue for his fifth Olympic bid.

[2][22] Having lifted a two-year doping suspension in November 2012, Paulissen announced his official comeback from a short retirement to join and ride for Italy's Torpado Surfing Shop Team at the start of the 2013 season.