Something strange happened on the podium at Jerez after the first round of this year's MotoGP. It wasn't that reigning world champion Valentino Rossi had just won another race. Or that it was Rossi's sixth win at the track on five different machines in four different categories. And never mind the fact that he had just broken another lap record, his 32nd in the premier class. It was the crowd's reaction to the charismatic Italian. Instead of the usual cheers that greet Rossi's victories, he was booed and jeered. Unused to such hostility and uncomfortable as being cast in the role of the bad guy, he took up a defensive posture that in turn encouraged the hecklers. The reason was Rossi's aggressive overtaking move on the inside of the final bend of the race that forced local favourite Sete Gibernau off the track. Gibernau stayed upright to finish second while Rossi went on to notch up another win. In traditionally flamboyant style he crossed the line pulling a wheelie. For the impish star the manoeuvre was just another weapon in his racing armoury - an acceptable part of the high-speed battles that make up MotoGP. 'I like to exit the corner a centimetre from the edge of the track,' Rossi has said. 'People tell me to give it more room, but to me the line is like a poem. Sometimes I crash because of my passion for the line.' And it's this passion that has seen him claim six World Championships so far, and he is only 26. Broadcaster Julian Ryder has said of Rossi: 'We simply do not know where this man's limits are as yet.' His innate skill seems to course through his veins and he seems to be able to squeeze something extra out of the 990cc machine, be it sheer power, braking or cornering. He keeps total control while riding like most great champions and rarely falls. Motorcycle racing really is in his blood. His father Graziano, won his first 250cc Grand Prix in 1979, the year Valentino was born. The young Rossi, who uses his father's racing number 46, first competed in karts then mini-motos before claiming a domestic 125cc championship in 1994. He entered grand prix racing in 1996, winning the world 125cc crown the following season. Two years later he added the 250cc series and then progressed to the blue ribbon 500cc class and won the final title in 2001 on a Honda. The following year Rossi, now nicknamed the Doctor, became the first MotoGP champion riding for Honda. In 2003 he retained the championship but then stunned the racing world by switching to rivals Yamaha in 2004 - and winning. Aside from Rossi, only three riders, Giacomo Agostini, Mick Doohan and Mike Hailwood, have won four or more consecutive premier class titles. Yamaha president Toru Hasegawa summed him up in November when he presented the Italian with last year's winning bike. 'Valentino Rossi is more than the world's best motorcycle racer. He is a personality that is not limited to just the confines of the MotoGP championship,' Hasegawa said. 'From the moment you work with Rossi you instantly become a fan, and you are naturally driven to give more than 100 per cent to support him. It is this very trait, and his ability as a rider that led to him winning the world title in his first year.' Rossi's natural skill and flair has already made him a fans' favourite. He has an infectious appeal with his almost innocent boyish charm and his mop of curly brown hair, big eyes and long sideburns that don't fit the tailored image of other sports figures. He is also a prankster and dons his doctor's coat and a stethoscope at races while he has had friends dress up as policemen to book him for speeding. During a victory lap in Spain he stopped to put on flip flops and used a portable toilet. Last July, prior to the British GP more than 5,000 fans packed Leicester Square to meet Rossi in his adopted home town. 'It was a fantastic afternoon,' he said. 'I live in London and so it's almost like meeting my home fans although there were plenty of Italians there.'. He received a welcome more fitting for a film star than a biker and went on to win the race. And as this year's championship progresses, Rossi, who is already facing tough opposition, may have to rely on his fans for that same moral support if he wants to retain his crown. But whatever the outcome of this season, as Doctor Rossi chases his fifth successive title he is already being hailed as the most successful motorcycle racer of all time.