McLaren's cool Finn lapped nearly a full second clear of the field, filled up by every other team except Sauber - at Monza - and cash strapped Minardi.
Interestingly, of the fourteen runners in overcast Northamptonshire, Pedro de la Rosa - whose Mercedes V10 failed - was the only non-race driver. Toyota's Jarno Trulli, for example, flew in from Monza.
"After the frustration of not running at all yesterday," said Renault's Christian Silk, "it was good to get some serious running done today."
Over at Monza, Sauber's Felipe Massa took over from Jacques Villeneuve but the Brazilian was outpaced by Ferrari test driver Marc Gene, the only other car on track.