Jarno Trulli, driving for Renault, started alongside Barrichello on the front row and led the first eleven laps of the race, until a track invasion by a later-to-be-defrocked priest, who ran along Hangar straight, running opposite to the 170 mph (280 km/h) train of cars, wearing a saffron kilt and waving religious banners.

Of the leading contenders, Trulli was in fourth place while both Räikkönen and Ralf Schumacher had jumped Barrichello when in the pits.

Barrichello continued to cut the advantage, but Räikkönen regained the lead with a reduced margin following the Brazilian's second stop.

Michael Schumacher eventually passed Trulli on the 46th lap, but an unforced error by Räikkönen allowed Montoya to seize second position.

He was later charged with aggravated trespass and pleaded guilty in a Northampton court,[6] stating that he took the open gate as a sign from God, although the prosecution contended that his act was premeditated as he had already prepared the banners prior to attending the Grand Prix.

The incident prompted comparisons to the events at the 1977 South African Grand Prix, where volunteer track marshal, Frederick Jansen van Vuuren, ran across the main straight to aid a car and was hit at 170 mph by Tom Pryce, who could not see him until it was too late because of the steep crest on the straight.

A similar incident occurred at the 2000 German Grand Prix (coincidentally won by Barrichello) when a disgruntled ex-Mercedes employee walked along part of the circuit in protest before being arrested.

Unlike the German protester, Horan ran directly down the middle of the track, and intentionally towards oncoming cars and lurching towards some of them.

Stephen Green, the marshal who handled Horan, was later awarded the BARC Browning Medal for "outstanding bravery in tackling a track invader during the 2003 British Grand Prix at Silverstone", the second recipient after David Purley 30 years previously.