Up until five years ago, Fernando Alonso could have walked past Michael Schumacher without either man recognising the other.

One was a little-known Spanish teenager, the other a champion well on his way to becoming Formula One's most successful driver with Ferrari but still no more than a famous name to Alonso.

"Formula One in Spain was nothing, like an American sport that you never see on TV," the 23-year-old championship leader said in an interview.

"I knew of Michael because I was racing in go-karts and you always know the big names in F1," he told Reuters. "But I didn't know his face until five years ago."

They know and respect each other well enough now, while Formula One has taken off in Spain thanks to the youngster's efforts.

The first Spaniard to lead the championship heads for the San Marino Grand Prix at Imola next week having won the last two races for Renault and with a 10-point lead over Toyota's Jarno Trulli.

While Alonso has 26 points, Schumacher has two. Despite the points disparity, Alonso still expects Schumacher to be the danger man once struggling Ferrari get their act together.

"They will catch up, unfortunately. There is a very long season and they know what to do and I'm sure that they will come back," he said.

When that happens, the 2005 season will be a battle between the man who would be king, as well as the youngest champion in the history of Formula One, and the German who has seen off every pretender to his throne so far this century.

Alonso is already assured of leading the championship to his home race in Spain next month and, with Monaco following Barcelona, probably well beyond.

The soft-spoken Spanish driver, an ardent Real Madrid fan despite coming from Oviedo in the northern Asturias region, remains quietly cautious.

"I think July is probably the key month with four races," he said. "After that, there are just five or six. I'm really confident. I know the team are preparing good improvements to the car. We will do all we can for the title but you never know in Formula One until the last two or three races."

Imola, Ferrari's home circuit and the first grand prix of the European season, will be a very different test after Australia, Malaysia and Bahrain. Even if the weather is cooler, Renault can expect the competition to hot up.

"There is room for improvement (for Renault) but less than the others," said Alonso.

"There are a lot of pictures of our car now with the other teams so it's normal that we will be a little bit less competitive at every race compared to the others.

"We will not go down but the gap with the others will be less. We hope to keep just a little room... at the moment we have no worries at all."

Alonso said Renault would have a new aerodynamic package for Imola that seemed 'very promising', as well as an engine upgrade for Spain. "So also the team is pushing a lot," he said.

After his win in Malaysia last month, Alonso saw for himself just how popular he had become in Spain when his parents' house was besieged by fans and the media.

When he made his debut for Minardi as a teenager in 2001, Pedro de la Rosa was Spain's leading light at Jaguar. But even then, F1's popularity was a distant third to that of motorcycling and rallying.

Until Alonso came along, the dashing Alfonso de Portago's second place for Ferrari at Silverstone in 1956 was the best any Spanish driver had ever managed.

That changed in 2003, with Alonso in Malaysia becoming the first Spaniard and youngest driver to start a race on pole position and then the youngest winner in Hungary.

The success of Schumacher, who also paid little attention to F1 as a youth, gave the sport a similar boost in Germany in the early 1990s.

Oxford retreat

The similarities between the two men do not stop there. Alonso began karting at the age of three while Schumacher started at four.

While Schumacher lives a family idyll in rural Switzerland, Alonso also prefers the quiet life well away from his compatriots.

Other drivers have embraced the millionaire Monaco lifestyle with luxury yachts and fast cars but home for Alonso is the English university town of Oxford.

"It's perfect," he said. "I get recognised maybe once a month... I go to the supermarket, I go to buy the newspaper and I can be there with friends. In Spain I have people in front of the house so it's impossible.

"The weather is the biggest problem I have."