first front-runner to make a scheduled pit stop on lap 18, rejoined in tenth. During the next two laps Salo passed Irvine for twelfth, whilst Barrichello made a pit stop from sixth position and came out in eleventh. By lap 21, Michael Schumacher had increased his lead over Häkkinen to eleven-and-a-half seconds. Ralf Schumacher, ten seconds behind Häkkinen, led teammate Button by six seconds. Michael Schumacher made a pit stop on that lap that took 11.1 seconds to complete, emerging in third position. On lap 23 Barrichello passed Herbert for ninth position, and during the next two laps Villeneuve and Ralf Schumacher made pit stops. Button made a pit stop from fourth position on lap 26. Häkkinen entered the pit lane one lap later after holding five more laps of fuel than Michael Schumacher; Häkkinen was told by his team (on pit boards) to speed up to gain on Michael Schumacher, who had a heavier fuel load. Button dropped to eighth position, and Häkkinen came out behind Michael Schumacher. Frentzen and Coulthard made their pit stops together on lap 28, with Coulthard emerging ahead of Frentzen. On that lap, Barrichello passed Alesi for sixth position. Barrichello, setting the fastest lap of the race (1 minute, 53.803 seconds on lap 30), had consecutive fastest laps before making his second pit stop on lap 31. However, his car's fuel pressure dropped which caused him to run out of fuel and he was pushed by marshals into the pit lane. Barrichello and Alesi (who had a similar problem caused by a fractured fuel system) retired, and Button inherited fourth place. Salo was the final scheduled driver to make a pit stop, on lap 33. At the end of lap 34, after all scheduled pit stops, the running order was Michael Schumacher, Häkkinen, Ralf Schumacher, Button, Coulthard, and Frentzen. During that lap Michael Schumacher's tyres began to degrade, and he ran off the racing line to cool them by driving through water; Häkkinen gradually closed the gap, due to his McLaren having a straightline speed advantage on the straights, and he began duelling Michael Schumacher for the race lead as the track had become completely dry. Coulthard, fifth, passed Button on the outside entering Les Combes corner for fourth position on lap 37. Häkkinen tried to pass Michael Schumacher on the inside for the lead on the 40th lap on the approach to Les