It could not be easier: go to Interlagos with a seven-point lead over Felipe Massa, of Ferrari, regarded by many as susceptible both in racecraft and temperament, and all Lewis Hamilton has to do is finish fifth or better should Massa win the final race of the season and the World Championship will be his. Surely Hamilton can close this one out, after a cool and collected victory in Shanghai yesterday when he led from start to finish, and there will be no repeat of the heart-rending last-gasp failure of last year.

If only Formula One was that simple. In reality any race that Hamilton is likely to have to finish to become champion is a risk. He may get tangled up in a mêlée at one of the tightest and most dangerous first corners the sport has to offer. He may find that, for the second year in succession, his McLaren Mercedes, mysteriously or otherwise, suffers its one and only mechanical failure of the season.

Alternatively Hamilton may suffer another one of his rushes of blood to the head and do something utterly unnecessary at Interlagos, just as he did in Japan eight days ago and in Brazil last year, and throw it all away. And what about the stewards who have played such a big role in Hamilton’s second year in Formula One? Could his driving attract their interest yet again, either in qualifying or the race, and lead to him being penalised out of a title that once again seems so close?

Then there is McLaren to contend with, an outfit with a talent for procuring defeat from the jaws of victory and renowned for finding it difficult to think on their feet when races develop in unexpected ways. And what about Interlagos, the pulsating heart of Brazilian motor racing; how will that influence matters? The old circuit in the slums of São Paulo will be packed to the rafters with thousands of fanatical Massa fans, invoking the spirit of the late, great Ayrton Senna and beating their drums to inspire their hometown hero to Brazil’s first world title since 1991.

Suddenly defending even a seven-point lead sounds a tall order. And you can see what an uncomfortable experience that afternoon in Brazil in two weeks’ time could become for the millions of Hamilton fans watching from behind their sofas back home as their man bids for the second time to become Formula One’s youngest world champion and Britain’s first since Damon Hill in 1996.

But what about the plus side for Hamilton? As long as the experience of last year does not return to haunt him, the 23-year-old, who now lives in tax exile in Geneva, should be able to use it to his advantage to help him to cope with the challenge of putting Massa to the sword in front of his rival’s home fans. Hamilton’s mature winning drive in the Chinese Grand Prix yesterday reminded us that he can compete sensibly even under extreme pressure and that, perhaps, he has finally understood how to control his aggression to close out a title race.

Although Hamilton’s lead over the Brazilian is the same size as the one he held at the equivalent time last year over Kimi Raikkonen, there is a big difference in his favour this time in the absence of Fernando Alonso from the equation. Last year Hamilton was locked in a bitter and very personal feud with the Spaniard — then his disaffected team-mate at McLaren — and it was Alonso, four points behind him, not Raikkonen who was on his mind when they climbed into their cars at Interlagos.

Alonso was driving the same machinery as Hamilton, he had been putting increasing pressure on the British rookie with a series of strong performances leading up to Brazil and he was on the scent of a third consecutive world title of his own. That the world champion was a huge factor in Hamilton’s thinking became all too obvious when, having been jumped by him at the start, the Briton rashly counter-attacked and ran himself off the track, dropping to eighth place from second on the grid. This time Hamilton only has to think about Massa, especially now that Robert Kubica, the BMW Sauber driver who was sixth in China yesterday, is no longer a contender.

Hamilton has been saying for some time that he believes his 2008-generation car, the McLaren MP4-23, will be more competitive at Interlagos than last year’s model and he repeated that again yesterday after showing a turn of speed at the Shanghai circuit that the Ferrari drivers could not match.

However, car performance is notoriously unpredictable in Formula One and what worked in China may not work in Brazil. What is more, unlike Massa, Hamilton goes into the showdown in Brazil with the same engine that he used in China, so that will be a worry.

What of Massa’s chances? The likeable Brazilian knows he has to race to win at Interlagos to give himself a chance but even then the destiny of the title will be out of his hands. Some say he will thrive on the atmosphere at his home track, where he drove brilliantly last year before allowing Raikkonen through to take the win. Among them is his mother, Ana Massa, who told The Times recently that she had no doubt her son would cope if it came down to the wire in São Paulo.

Others are not so sure. They see in Massa someone of frail temperament who can lose the plot if he finds himself up against it and who may find the pressure of expectation, with the voices of his countrymen exhorting him to succeed in one ear and the ghost of Senna whispering in the other, too much to take. There is also a sense in which Massa may feel added pressure born in the knowledge that this may be his one and only chance at Formula One glory if, as some predict, Raikkonen returns to form with a vengeance next year.