Estoril test - day four: 10 February.

Jean Alesi continued to set impressive times with the new Prost-Ferrari, topping the tables at Estoril ahead of both Benettons.

The fiery Frenchman, who had already proven quickest of all on the opening day of the Portuguese sojourn, lapped fractionally quicker than Benetton new boy Jenson Button on day three. Accused of running with new tyres and low fuel loads earlier in the winter season, Prost's Saturday times were believed to be on the level, giving the whole team a morale boost as it seeks to overturn the nightmare of last year.

Alesi's performance was backed up by the surprising pace of new team-mate Gaston Mazzacane, who found some of the two seconds by which he had trailed the Frenchman last week and ended the day closing on Button's best effort. The Argentine was having only his second real outing in the AP04, but proved quicker than the new Benetton B201 in the hands of Giancarlo Fisichella.

The Italian was again charged with running the latest product from the Enstone stable, while Button campaigned the older B200B previously used by test driver Mark Webber. While Button was neatly sandwiched between the two darker blue Prosts, Fisichella again trailed some way off the ultimate pace, almost a second behind Alesi.

Arrows, which had contested the opening couple of days at Estoril, was conspicuous by its absence as it headed for the warmer, drier, climes of Valencia.

Leading performances (10 February):

Jean Alesi Prost-Ferrari 1min 21.2secs*Jenson Button Benetton-Renault 1min 21.3secs Gaston Mazzacane Prost-Ferrari 1min 21.4secs*Giancarlo Fisichella Benetton-Renault 1min 22.1secs*

[* denotes 2001 car; all drivers on Michelin tyres]