BUDAPEST (REUTERS) - Lewis Hamilton scorched to his third pole position in a row for Mercedes in searing track temperatures at the Hungarian Grand Prix on Saturday.

The 2008 world champion, a three-time winner in Hungary with McLaren, lapped the Hungaroring circuit with a best time of 1min 19.388sec to deny Red Bull's Sebastian Vettel the top slot.

Three-time world champion Vettel, who leads Ferrari's Fernando Alonso in the standings by 34 points after nine of 19 races, could manage only 1:19.426 with the track temperature hitting 50 deg C earlier in the session.

Frenchman Romain Grosjean qualified third for Lotus, with Hamilton's German team-mate Nico Rosberg fourth. Alonso will start fifth.