Free Practice 4: Rubens tops, Schuey Jr impresses

Tyre war adversaries Michelin and Bridgestone had surmised that Sepang would not see lap times tumble as spectacularly as in Melbourne a fortnight ago, but Barrichello's 1m36.188s pointed to a slight under-calculation from the two companies.

The last Malaysian GP was only five months ago, but Barrichello's hot lap was still a full 1.209s below the 2000 pole - not as big a fall as in Australia, but still significant given the timescale and the fact that the 2001 cars have considerably less downforce than their immediate predecessors.

Schumacher set his quick lap with just seconds of the 45-minute session left to run. The German's Williams took over the mantle of top Michelin runner from Eddie Irvine, who had to settle for eighth fastest - the only other Michelin user in the top 10.

Third quickest was McLaren-Mercedes driver Mika Hakkinen. Along with team mate David Coulthard, the double world champion's MP4-16 sprouted a pair of nose fins designed to increase front end downforce that gave the car the appearance of a silver frilled lizard. Whether they worked or not, the Finn pipped Ferrari's reigning world champ Michael Schumacher into fourth by 0.029s, with Coulthard 0.266s back in fifth.

Heinz-Harald Frentzen just edged his Jordan-Honda team mate Jarno Trulli for sixth, with Olivier Panis's BAR and the Sauber of top rookie Kimi Raikkonen in ninth and 10th behind Irvine.

Nick Heidfeld's Sauber lined up 11th, 0.021s behind Raikkonen, with Jacques Villeneuve 12th in the second of the BARs.

Juan Pablo Montoya continued on his accelerated learning curve in the second of the Williams-BMWs, but spun early in the session as he got to grips with the Sepang layout.

Benetton-Renault began its climb up the field with 16th and 17th for Giancarlo Fisichella and Jenson Button respectively, with Minardi's Fernando Alonso dropping back to finish 21st, just ahead of his boony-visiting team mate Tarso Marques.

The single hour of qualifying begins at 13:00 local time (05:00 GMT), with track temperatures expected to reach nearly 50 degrees C and air temperature likely to make a nodding acquaintance with the 40-degree mark on the thermometers.

For full results click here.