HOCKENHEIM, Germany, July 18, 2008 (AFP) - Briton Lewis Hamilton led the way in Friday´s opening rain-hit practice session for Sunday´s German Grand Prix.

The 23-year-old McLaren ace clocked the fastest time as he maintained his resurgent form ahead of his team-mate Heikki Kovalianen.

The two McLaren men were ahead of the field with the Ferraris of Brazilian Felipe Massa and defending drivers world champion Kimi Raikkonen third and fifth quickest.

The two red cars were split by two-times champion Fernando Alonso in a Renault in a session when positions changed rapidly in the final stages as the circuit dried out.

Early-morning rain had left the track wet for the opening part of the session, but after further light showers the conditions improved and several drivers claimed top spot in the process.

German Sebastian Vettel of Toro Rosso, who is to switch to Red Bull next season, and then Hamilton and Alonso, all running on intermediate tyres, took turns as fastest man.

Hamilton had a spin at Turn Four and escaped unscathed before the Ferraris moved to the front after 35 minutes.

As the rain eased, each fast lap set a fastest time for a period until the drivers all switched to dry-weather tyres.

Massa appeared to be the quickest man towards the end of the morning, but his best time was overhauled by Kovalainen and then Hamilton in the final seconds.

Hamilton´s best lap was one minute and 15.537 seconds, just one-tenth better than that of his team-mate and a further tenth ahead of Massa.

Pole Robert Kubica spun off in the stadium section and hit the barriers, but escaped injury and damage.