In 1998 Noriyuki turned his attention to racing full-time in the World Superbike class, adopting the number 41 that he has used ever since. In that year he won five races and concluded the season in sixth position, despite never having seen many of the circuits on the calendar before. He went on to finish seventh in the standings in 1999 and then followed this up with a much stronger performance in 2000, when he took 4 wins and 11 podiums, to close the season as vice-champion behind title winner Colin Edwards.
In 2001 and 2003 Noriyuki moved across to the MotoGP series, racing a WCM Red Bull-sponsored Yamaha 500cc motorcycle in 2001, and with MS Racing's MotoGP Aprilia in 2003. He had two difficult seasons and finished both in a disappointing fourteenth position, his best result a fourth place finish in 2001.
2002 was a winless season in World Superbike but a return to the category in 2004, riding this time for the Renegade Ducati team with the Ducati 999 RS, saw Noriyuki in contention for the title right up until the final round. He won six of the season's races, before eventually finishing third in the standings. This performance was repeated in 2005, this time riding for Yamaha's factory team, with ten podium places, and again in 2006 after scoring eleven podium place finishes.
The battle that Noriyuki fought against James Toseland in 2007 led to the closest championship finish to date, a year in which Noriyuki clocked up six race wins and fifteen podium places, including the double win at the final round of the season in Magny-Cours. Despite all this, he still had to settle for second place, just two points behind title winner James Toseland. In 2008 Noriyuki continued on with the Yamaha Motor Italia team for the fourth consecutive year, and a strong set of results that included a double win at Nurburgring and Vallelunga meant that he closed the year in third position behind second-placed man and team-mate Troy Corser, and Troy Bayliss (Ducati Xerox), crowned World Champion in 2008 for the third time.
In 2009 Noriyuki took over from the retired Troy Bayliss in the Ducati Xerox Team. The Japanese rider was immediately at ease on the Ducati and won the very first race of the season at Phillip Island. Nitro-Nori followed this up with seven further race wins and a total of nineteen podium finishes during the year, including double wins at Valencia and Kyalami. At the penultimate event of Magny-Cours, Noriyuki's eighth race win of 2009 awarded the Ducati factory Superbike team it's sixteenth manufacturers title. The fight for the riders title however went down to the wire, with Noriyuki heading to the final track of the season, Portimao, just ten points ahead of second placed man Ben Spies on the Yamaha. The spectators were treated to two spectacular races in Portugal, the first of which was won by Spies and the second by Fabrizio with Noriyuki crashing out of race 1 and finishing second in race 2, to lose out on the 2009 World Superbike riders title by just six points. By the end of 2009, the Japanese rider had accumulated a career total of 106 podium finishes, beaten only by Carl Fogarty (109) and Troy Corser on 128.
Noriyuki will continue with the Ducati Xerox Team in 2010.
