The next three races will be critical for Alonso

Lewis Hamilton upstages team-mate Fernando Alonso on the road to Monte Carlo, says Maurice Hamilton

It says much about the extraordinary turn of events inspired by Lewis Hamilton in the first four races that Fernando Alonso is suddenly being viewed as a member of Formula One's old guard. The title holder is only 25, just 12 months older than Ayrton Senna and seven years Damon Hill's junior when these prospective world champions made their F1 debuts.

Alonso rightly expected to continue his form as the man to beat when he switched from Renault to McLaren at the beginning of the season but the Spaniard is as surprised as anyone by the astonishing progress of his 22-year-old team-mate.

Alonso has made polite noises about never having underestimated the potential threat offered by Hamilton in the other McLaren-Mercedes but even Alonso, noted for his understated demeanour, must have been rocked by Hamilton's ability to step into a 195mph F1 car and race it as if to the manner born. Hamilton has become the youngest driver ever to lead the championship and Alonso can only reflect that he gave the novice a helping hand on that Sunday by making a mess of the first corner of the Spanish Grand Prix. Alonso's dusty excursion across the gravel trap not only relegated the home hero to an eventual third place but it also exposed his only weakness.

Until his arrival at McLaren, Alonso had always managed to dominate his team-mate. On the rare occasions when Giancarlo Fisichella had the measure of Alonso during their partnership at Renault, Alonso's mask of cool respectability would slip to reveal sometimes irrational behaviour. Now there is the previously unimagined threat of self-doubt taking permanent hold as Hamilton proves to be at least Alonso's equal after just four races, an extraordinary feat considering the experience accumulated by Alonso during 92 Grands Prix.

The next three races in Monaco, Canada and the United States will be critical for Alonso and could establish a pecking order that McLaren, for all their commendable even-handed dealings with both drivers, might find difficult to ignore as the season heads towards half distance at Silverstone's British Grand Prix on July 8.

Monaco is the worst place in the world for a driver who feels the need to prove himself. The narrow track calls for precision and punishes desperation of the type exhibited by Alonso as he tried vainly to take the lead in Barcelona. Hamilton, on the other hand, will travel to Monte Carlo with an inner confidence that is born of his recent success and an inherent love of the street circuit and its special demands. He has raced three times in various junior formulas at Monaco and dominated on each occasion.

Hamilton may not be familiar with either Montreal or Indianapolis but he will go to North America knowing that Alonso hit the wall at the former (when in a fit of pique over Fisichella's progress in 2005) and has a mental block over the latter, never having finished higher than fifth. Speaking on his team's official podcast, Renault's team manager, Steve Nielsen, summed up Alonso's potential difficulties. "In his career, Fernando has always been comfortably faster than team-mates, and now he's got a guy who's his equal, if not maybe a little bit quicker in the races, as we've seen so far," said Nielsen. "I think he'll be questioning himself, deep down inside, as to whether he is really quicker than his team-mate.

"The few times we saw Fernando really under pressure were when his team-mate beat him. That's the situation he's in now."

If Hamilton continues to rack up championship points at Alonso's expense, then it is likely that his only serious championship rival may be Felipe Massa, the winner in Barcelona. Hamilton has forced Alonso onto the defensive and Massa has done the same to Kimi Raikkonen, who was supposed to exert in-house superiority at Ferrari similar to the authority Alonso clearly expected to establish within McLaren. When Massa and Hamilton exchanged post-race congratulations at Barcelona, there was an unmistakable aura of impish mutual respect from two juniors who suddenly realised they had their de facto team leaders on the run.

Hamilton dispatched Raikkonen during the dash to the first corner in Spain, Raikkonen's misery later compounded by an electrical failure that brought early retirement. It was a familiar experience for the Finn, Raikkonen having left McLaren because of reliability problems that cost him two world titles over the past five seasons.

It is Raikkonen's continuing bad luck that McLaren appears to have turned the corner by being the only team to have scored points with both cars in every race. Conversely, it may be Hamilton's good fortune that he has arrived at precisely the right time, but that does not detract from what appears to be an exceptional talent that allows him to play havoc with his team-mate's reputation.

Pat Symonds, executive director of engineering at Renault, admits to being surprised by the sight of his former driver under pressure. "It would be a brave man, but probably not a very honest man, who said he could have foreseen Lewis giving Fernando a hard time," said Symonds. "Certainly I couldn't, and it's been a big surprise. At Renault, we know exactly what Fernando is like. We know what Lewis is up against, and for him to go against him and at least be the equal of him is, to me, absolutely amazing."

@ Guardian Newspapers Limited 2007