Lewis Hamilton opened his championship defence with a strong showing in the opening practice session for the Australian Grand Prix on Friday afternoon.
The Mercedes driver topped the 90-minute session with a 1:24.026 – beating his chart-topping first free practice time from 2017 by two tenths.
Mercedes team-mate Valtteri Bottas was second quickest, albeit half a second down with a 1:24.577, narrowly ahead of Red Bull's Max Verstappen in third.
The opening session of the year began with Sergey Sirotkin setting the first timed lap and also his first official timed lap in F1 as he makes his debut with Williams, although that was quickly beaten and the times began to tumble after the first 30 minutes of running as teams completed their installation laps.
There was little in the way if incidents other than Sirotkin brushing the pitlane wall as he returned to his garage, though he escaped any damage and was back out after a quick check by his mechanics.
As predicted during testing, the top three seem to be Mercedes, Red Bull and Ferrari as Kimi Raikkonen popped up into fourth ahead of team-mate Sebastian Vettel, the duo some way off Hamilton's best time though and will therefore be looking to make some gains in second practice this afternoon.
Daniel Ricciardo completed the top six with Haas' Romain Grosjean seventh, seven-tenths down on the Australian and more than 1.7 seconds off the top.
Fernando Alonso was eighth although he only completed 15 laps as both McLarens hit trouble. Stoffel Vandoorne was tenth quickest – the pair split by Renault's Carlos Sainz – as the team reported exhaust problems which limited the pair's running to a combined 29 laps, the same number achieved by Force India Esteban Ocon alone.
Sauber's Charles Leclerc completed the timing sheets in 20th, 4.8 seconds adrift and almost a second behind his Sauber team-mate Marcus Ericsson.