Refreshed Button's fine form pleases Briatore

The hand that not so long ago was raised in near despair now grasped Jenson Button's shoulder with paternal affection. It was further evidence that the young Englishman had won over Flavio Briatori, Renault's demanding team principal who, disappointed in Button's form last year, was not alone in citing the negative effects of instant stardom on his driving.

This year, however, Button is responding to the potential of a much improved car – his fifth place in Sunday's San Marino Grand Prix kept him in fourth place in the World Championship. "Great drive," Briatori told Button, who rated it the best of his career to date.

Button contends he never neglected his work, but is in any case focused on the future. To catch and push David Coulthard's McLaren into sixth was "mega", he said. "It's the first time we have beaten them for pace and it feels fantastic."

Renault believe they can realistically take third place in the constructors' championship from McLaren but Button is training his sights on the champions Ferrari, whose Michael Schumacher and Rubens Barrichello finished first and second in San Marino. He said: "I don't think Ferrari are unbeatable. We are working to get there."

Realism has hit Coulthard too – the Scot appears ruffled by Button's challenge. Coulthard said: "Jenson has had good races and naturally I believe he had a quicker car on the day here, otherwise I would be in the wrong business. Renault have not out-qualified us this season and in only one of the four races have they been ahead of us. I don't think you can call that serious competition. I am not trying to belittle their performance, and maybe over the course of the next 13 races they will be stronger than us, but one swallow doesn't make a summer."

Coulthard, who was also out-paced by his team-mate Kimi Raikkonen, until the Finn had to retire, was unhappy with his car and remains convinced of his own ability. He said: "My goal will be to be quickest and win in Barcelona. I don't see why I should lower my sights but unless we find something in the test this week it is unlikely that our performance will be closer to the front than it was here.

"There is no reason to believe Ferrari will be any weaker at any particular race. It is a bit grim but there is no point in sticking your head in the sand. We have to keep working. Things are not as bad as they looked here."

Coulthard and his team had been conspicuously uneasy all weekend. They felt they had an excellent car going into this season but concerns about the Mercedes engine appear justified. Ron Dennis, the team principal, said: "I believe we are going to win races this year. At the moment we're just not quick enough, we recognise that. We need to be better on all circuits.

"We don't hide from a lack of performance. It's painful in Formula One if you're not quick enough but we are up front about that. Openness comes at a price – it's embarrassing when you're not quick and at the front of the grid. But we're fighters. We take it on the chin and come back. We'll get it right."

One consolation for Dennis is the pace and application of 22-year-old Raikkonen, recruited from Sauber to replace Mika Hakkinen, who is on sabbatical. Dennis said: "I think it was the right decision to take Kimi. He is getting better by the race and keeping David honest. We're delighted with both of our drivers and know the lack of pace is not down to them."