It was a case of as you were for Mark Cavendish as he won his fourth stage of the Tour de France here yesterday, but with one difference: his margin of victory has extended to almost embarrassing proportions.

Embarrassing, that is, if you are one of his rivals, and Cavendish seemed almost apologetic when asked later if he had any sympathy for his fellow sprinters. It took the aerial view to reveal the true extent of his superiority. It showed the Manxman, crossing the line with arms outstretched in celebration, an almost nonchalant look on his face - and, about two lengths back, the rest of the field.

Behind the 23-year-old there has been a different challenger each time, and yesterday it was the turn of Robbie McEwen, the Australian who has claimed 12 bunch sprints in the Tour. Four stage wins for a sprinter is not unheard of - Alessandro Petacchi achieved the feat in 2003, as did Mario Cipollini, on consecutive days, in 1999 - but Cavendish joins a select group, and his exploits are all the more impressive for the fact that this year's Tour has had only four true bunch sprints.

Although his victory was decisive, yesterday's finish was the least straightforward of his four successes. With numerous teams battling for control at the front of the peloton, which had to negotiate roundabouts and other road "furniture" on a complicated run-in, his Columbia team struggled to give him the kind of lead-out he has been used to. In the final kilometre he had to fend for himself, and with 500 metres to go he looked boxed in.

Then, however, came the familiar sight of Cavendish, having manoeuvred himself into space, emerging at the head of the peloton, mouth wide open as the line drew closer. Before the stage, Allan Peiper, his team director, had said that it was as if the Isle of Man sprinter "can smell the line", and that was how it appeared yesterday.

Cavendish described the win as his most difficult of the four. "My first stage win was my favourite," he said, "but today was my hardest. I used my team up early and in the end I had to sprint in my usual fashion, jumping up [other teams'] trains until I was at the front."

Earlier his team manager, Bob Stapleton, had said that his rider was "extremely tired", adding that "the team is putting no pressure on him to finish the Tour. He is taking it day by day, because he has personal goals at the Olympics. Our biggest ambition is for his long-term development".

Cavendish began his winner's press conference with a request. "I know there's been another doping case today and, if you don't mind, I don't want to answer questions about that. I don't want somebody else to overshadow my victory today."

In fact, there was not a fourth doping case yesterday, though the fallout from Riccardo Ricco's positive test on Thursday, for a substance described as "third-generation EPO", continued. With Moisés Dueñas, who tested positive for EPO 24 hours before Ricco, having been charged on Thursday with the "use and possession of plants and poisonous substances", Ricco was charged yesterday, though in his case only with "use". The offence carries a two-year prison sentence, with Dueñas facing a further three years for possession. After being released from the police station in Pamiers, where he spent Thursday night in custody, Ricco returned to Italy.

The other development yesterday was that Ricco's veteran Italian team-mate, Leonardo Piepoli, who won Monday's Pyrenean stage, was fired by the Saunier Duval team. Though Piepoli has thus far failed no test, both he and Ricco were sacked, said a team statement, for "a violation of the team's ethics code".

Mauro Gianetti, the Saunier Duval director, who withdrew the entire team after Ricco's positive, admitted that he had confronted Ricco at the start of the season. The Italian "swore on his mother's head" that he wasn't involved in doping activities, said Gianetti.

Yesterday his immediate family sought to paint Ricco as a victim, with his sister, Melissa, suggesting that he was being hounded out the sport and comparing him to his idol, Marco Pantani, whose drug-fuelled descent to a lonely death in 2004 began with a failed blood test in 1999. "If someone is strong and exuberant like my brother they always find a way to get rid of you," said Melissa. "The same thing happened with Pantani."

The newspaper La Stampa also made the comparison, but less favourably, calling Ricco "a nauseous replica [of Pantani], a cheat disguised as a demigod".

Ricco's only public comments were made to an Italian television station, which intercepted him at a motorway service station. "All the police found [in my possession] was vitamins," he told them. Asked if he had used EPO he responded: "You'll find out in the next few days." Finally, and with yet more echoes of Pantani, he added: "I'll come back stronger. You haven't heard the last of me."