World champion Lewis Hamilton took up where he left off last season with the fastest lap times in opening practice for the Australian Formula One Grand Prix on Friday.
Hamilton followed up his opening practice best time of one minute 24.026 seconds with 1:23.931 in the second session to hold a 0.127sec gap over Red Bull's Max Verstappen (1:24.058).
Mercedes team-mate Valtteri Bottas (1:24.159) was third in Melbourne in the first exchanges of the new Formula One season.
The Ferrari duo of Kimi Raikonnen and Sebastian Vettel were fourth and fifth respectively and between 0.3-0.5secs down on Hamilton's time ahead of Saturday's qualifying.
Australia's big hope Daniel Ricciardo in a Red Bull was seventh fastest in 1:24.721.
Hamilton's long-run pace looked superior on the ultrasoft tyres, reeling off a steady run of 1:28s, but race pace simulations showed little between the three leading teams.
Red Bull managed to lap in the high 1:28s with Ferrari in the low 1:29s.
Verstappen and Bottas both used soft tyres for the final few minutes of the second practice session, while Raikkonen was on the supersoft for Ferrari.
Hamilton 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.
Bottas and Raikkonen faced the stewards after the session to explain a coming together, when Bottas had to take to the gravel to avoid running into the Ferrari.
The surprise of the opening day was the performance of the Haas team to challenge for the fourth-fastest team on the back of two strong showings from Romain Grosjean.
The second session was halted briefly after a cable was ripped up from underneath the start/finish line, and resumed after officials cut loose the wire.
A fired-up Fernando Alonso yelled down the McLaren team radio: "Maybe because of the halo the people stop looking into their mirrors!" after a close shave with some of his rivals early in the session.
The halo, a safety bar above the cockpit to protect drivers, is a new innovation this season.