(REUTERS) - Formula One world championship leader Charles Leclerc lapped fastest as Ferrari finished one-two in a wet first practice for their home Emilia Romagna Grand Prix on Friday (April 22).

The 24-year-old Monegasque lapped Imola's Enzo and Dino Ferrari circuit in a fastest time of 1min 29.402sec on intermediate tyres, with Spanish teammate Carlos Sainz 0.877sec slower.

Red Bull's reigning world champion Max Verstappen was third fastest with a time of 1:30.867, followed by the two Haas drivers Kevin Magnussen and Mick Schumacher, one of several spinners.

Red Bull's Sergio Perez was sixth fastest.

Seven-time world champion Lewis Hamilton was only 18th in a session that started with full wet tyres before conditions improved enough for some to venture out on intermediates.

Teammate George Russell, second in the standings but 34 points adrift of Leclerc, was in 10th place on a difficult afternoon for the champion constructors and more than four seconds off the pace.

Hamilton was seven seconds adrift of Leclerc.

"This is all about getting grip into the tyre and the temperature," said team boss Toto Wolff. "The Ferraris appear to have unlocked this thing and everybody else is pretty much all over the place.

"Certainly when you see your car pounding around five seconds off the pace, you want to strangle yourself. But I enjoy the challenge and I enjoy it being bad - because in the long run we're going to be good."

McLaren's Lando Norris brought out red flags five minutes from the end when he locked up at Acque Minerali and went into the gravel before getting back on track.

Imola is the first European race of the season and also the first of three in the sprint format, with qualifying later on Friday to decide the starting grid for a 100km race on Saturday that establishes the order for Sunday's main event.

In a change from last season, the official pole position for the Formula One record books will be awarded on Friday rather than Saturday.