Valtteri Bottas topped the timesheet as Mercedes set a scorching pace in Practice 1 at the Japanese Grand Prix.

The Finn would pip Lewis Hamilton by less than a tenth of a second posting a 1m28.731s on the soft compound tyre.

Perhaps a slight concern for the Briton was a fire on his front-right brake through the final chicane on his out-lap, but it didn't appear to slow him down despite sitting behind his teammate.

Certainly, it was a positive first track outing for the Brackley-based team's latest aero upgrade with the two Mercedes' almost a second clear of Sebastian Vettel in third for Ferrari.

There was a brief moment involving Bottas and Charles Leclerc at Spoon curve, with Valtteri locking up on a fast lap after being distracted by the slow-moving Monegasque.

However, the polesitter at the past four races would ultimately finish 1.1 seconds behind the 30-year-old in fourth.

With the weight of Japan on their shoulders, Red Bull can't have been too happy with fifth and sixth to start the weekend, and certainly the big gap to Mercedes will be a concern.

Max Verstappen was within two-tenths of Leclerc though, as he bids for a fourth straight podium at Suzuka, while Alex Albon sat a respectable three-tenths behind the Dutchman.

Carlos Sainz's day got off to the worst possible start as he pulled over with an engine issue exiting the pits for his installation lap.

Once fixed, the Spaniard returned to the track and claimed 'best of the rest' in seventh for McLaren, marking a solid recovery.

Right behind were the two Racing Point's of Sergio Perez and Lance Stroll, with the greater emphasis on downforce around Suzuka suiting the more recently upgraded RP01.

Lando Norris would round out the top 10 in the second McLaren.

As always the midfield pack was tightly bunched up with 1.3s covering P7-P17.

The notable drivers lower down the order included Kimi Raikkonen in 12th on a weekend when Alfa Romeo is expecting to be more competitive after struggling in Sochi.

Teammate Antonio Giovinazzi had a tougher time though, as an apparent gearbox issue saw the Italian crawl back to the pits, not to be seen again in Practice 1.

Renault also have work to do with Nico Hulkenberg and Daniel Ricciardo 13th and 14th respectively despite trialling a new front wing.

At Toro Rosso, Japanese star Naoki Yamamoto was delighted with his morning's work, finishing within a tenth of Daniil Kvyat albeit with the help of the soft tyre compared to the Russian on mediums.

Finally, at Williams, plenty of development work continues there with George Russell, in particular, using plenty of flo-vis to test out a new front wing.

The Briton also remained comfortably faster than teammate Robert Kubica with 0.7s the gap on Friday morning.

Full timings from Practice 1 in Japan can be seen below: