Lewis Hamilton. Pic/AFP

World champion Lewis Hamilton made an ominous start to the season as he led a Mercedes one-two in opening practice for the Australian Formula One Grand Prix on Friday. Hamilton clocked a best time of one minute 24.026 seconds among his 27 laps to be a half-second quicker than team-mate Valtteri Bottas (1:24.577) in Melbourne. The 33-year-old Briton is gunning for his fifth world title this year, an achievement which would match the legendary Juan Manuel Fangio and leave him just two adrift of Michael Schumacher's all-time record.