George Russell topped the times for Mercedes ahead of McLaren's Oscar Piastri in Friday's rain-hit opening practice for this weekend's Hungarian Grand Prix. In a wet session punctuated by crashes - including one by Red Bull's under-pressure Sergio Perez -- and red flags, Australian rookie Piastri clocked a best lap in 1min 38.795 sec to outpace Briton Russell by three tenths of a second. The Aston Martin of Lance Stroll was third quickest ahead of Lando Norris in the second McLaren, two-time world champion Fernando Alonso and Alfa Romeo's Valtteri Bottas.