Red Bull's Daniil Kvyat headed Mercedes drivers Nico Rosberg and Lewis Hamilton in a wet second practice at the Japanese Grand Prix.

The Russian beat Rosberg by just 0.023 seconds, with the world championship leader a further 0.553secs adrift.

Red Bull's Daniel Ricciardo was fourth ahead of the Ferraris of Sebastian Vettel and Kimi Raikkonen, all three having off-track moments in the rain.

The Ferraris were nearly two seconds off the pace of the front-runners.

Toro Rosso drivers Carlos Sainz and Max Verstappen were seventh and eighth.

Despite the unpleasant conditions, the ever-enthusiastic Japanese fans turned up in their thousands as always to watch the drivers they idolise and support with elaborate and often home-made hats, costumes and banners.

Japanese fans at the Japanese grand prix

A Japanese fan impersonates Sebastian Vettel's winning celebration and sports a hat in the style of the German's helmet

Fans with McLaren spoiler hats

Many racegoers made their own hats in the style of McLaren bodywork

All the quick times were set in the first half-an-hour of the session as the rain that has been falling all day was at its lightest.

For a while, as the mountains in the distance to the north emerged from the clouds, it looked as if there might be some dry running.

But before long the rain came down harder and one by one the drivers returned to the pits.

Asked what he had learned, Hamilton said: "Have you heard of the term diddly squat? That's what it is today. It has not been particularly fun. There has not been a lot to learn.

"The balance will be so much different tomorrow so it is irrelevant what we did today. You don't want to risk the car. It's a shame for the fans because a lot of them have turned up today."

In the closing half-an-hour, McLaren's Fernando Alonso, and Mercedes and Ferrari were the only drivers to do any serious running.

The Spaniard had been stranded in the pits earlier in the session because his car had needed an engine change after a problem was found with the one he used in the first practice.

He managed a 17th-fastest time. That was the fastest of the few cars out at a similar time on the extreme wet tyres, although Vettel went a second or so quicker in the last couple of minutes.

Alonso's team-mate Jenson Button, who did run in the driest part of the session, was 12th as speculation swirled about his future.

Following reports that he was on the point of announcing his retirement, Button said on Thursday that he was in "good talks" with the team about his future.

The 2009 world champion - who had told reporters after last Sunday's Singapore Grand Prix that he had "no joy" in running around towards the back as he has done this season - said he "understood" why the reports had been written.

But he gave no indication here whether or not he wanted to continue in F1.

McLaren chief operating officer Jonathan Neale admitted that "if you're driver doesn't want to stay, you have to respect that".

Nico Rosberg driving in the rain

The heavy rain made driving conditions difficult in the latter stages of second practice

Sources close to the situation suggest that Button, on whom McLaren have a contractual hold for next season, does in fact want to race on next year but it remains to be seen whether he and the team can reach an agreement that satisfies both parties.

The worsening rain meant Williams's Valtteri Bottas did not go out at all.

The Finn explained that the team did not want to use any more of the intermediate tyres - of which each driver only has four sets for the weekend.

"We decided not to use any new inters because we might need them if it is wet in the race," Bottas said as he waited in the pits.

"I grained my set this morning pretty badly so they were no use. We were going to wait for the dry but it looks like that is not going to happen."

The forecast is for warm, dry weather for qualifying and race over the weekend.

Japanese GP second practice results

Japanese GP coverage details