Valtteri Bottas claimed his first Formula One victory in 13 races at the Japanese Grand Prix as Mercedes won a sixth consecutive constructors' championship on Sunday.

Ferrari had secured a surprise front-row lockout in qualifying - which was moved to the morning of the race due to Typhoon Hagibis - but Sebastian Vettel paid the price for a poor start from pole position and had to settle for second place.

Lewis Hamilton was third and added another point for the fastest lap as his lead in the drivers' championship over Bottas was reduced to 64 points.

Max Verstappen had to retire after a first-lap incident with Charles Leclerc, who recovered to finish in sixth position behind Red Bull's Alex Albon and McLaren driver Carlos Sainz.

But Leclerc was demoted to seventh place and Daniel Ricciardo moved up to sixth after the race once stewards had investigated.

Mercedes became the second team in history to win six straight team titles after Ferrari's run with Michael Schumacher from 1999-2004.

And they are now guaranteed to be the first outfit to win six straight driver and constructor doubles, with Hamilton or Bottas the only drivers who can mathematically win the title.

After claiming a surprise pole for the first time in 10 races, Vettel had a dreadful start.

He mistimed his launch and Bottas surged up from third on the grid into the lead, though there was partial relief for the Ferrari as no action was taken after an investigation over whether he had jumped the start.

In an explosive beginning to the race, Verstappen was hit by Leclerc at turn two, the Monegasque dropping to the back after pitting for a new front wing and the angry Red Bull star, who spun off track, ultimately having to retire on lap 15.

Hamilton was frustrated over Mercedes' strategy on team radio after coming out of the first round of pit stops 10 seconds behind Vettel in a distant third place, having stayed out for longer than the German and team-mate Bottas.

The Briton was leading the race when Bottas and Vettel pitted for the second time and may have briefly pondered staying out in a one-stop strategy as he asked his team what he could do to win, having earlier bemoaned being "out of the race".

But when he eventually made his next stop due to degradation, he came out five seconds behind the Ferrari on significantly fresher tyres.

With five laps to go, Hamilton had caught Vettel but the Ferrari's straight-line speed meant the German remained ahead to cling on to second spot, adding to the championship leader's frustration.

Bottas, who had shown the fastest Friday pace before Ferrari's qualifying surprise, was left to claim his third victory of the season and first since Baku in April.

LECLERC & VERSTAPPEN CLASH

Following his incident with Verstappen, Leclerc initially stayed out despite visible damage to his front wing, with his wing mirror soon falling off completely as Hamilton behind questioned why he had not been ordered to stop.

Ferrari had been advising Leclerc to pit and he eventually opted to do so on lap four, coming back out last and having to work his way through the field.

Initially race stewards said there would be no investigation but on lap seven they appeared to have changed their mind as they began looking into it, before saying they would continue their review after the race.

Verstappen stayed out towards the back but Red Bull team boss Christian Horner confirmed the damage incurred was "aerodynamically significant".

The Dutchman complained about movement under braking and was then passed by Leclerc in a battle for 16th on lap nine, shortly before the decision was taken to retire his car.

"What more does he have to do to get a penalty?" Verstappen asked after his retirement before going on to label Leclerc "irresponsible".

After the race, Lerclerc received 15 seconds' worth of time penalties - five for his role in the incident and 10 because Ferrari, who were also fined €25,000, did not pit him soon enough.

SAINZ AND RICCIARDO IMPRESS IN MIDFIELD BATTLE

Sainz was once again the class of the midfield cars with an excellent fifth-place finish, his fifth top-six finish in the last eight races.

Ricciardo impressed for Renault with a drive that saw him end up sixth having started 16th, a long first stint being rewarded as well as Leclerc's penalty working in his favour.

Lando Norris ended up outside the points in 13th after coming off second best from a lap-five scrap with Albon, who went unpunished despite the McLaren driver's claims he had been forced off the track.

After the race, it emerged that a chequered flag display signal had been shown one lap too early, meaning Sergio Perez was credited with finishing ninth despite crashing out on what was supposed to be the final lap, pushing Nico Hulkenberg down to 10th and costing team-mate Lance Stroll a point.

IN THE POINTS

1. Valtteri Bottas (Mercedes)
2. Sebastian Vettel (Ferrari) +13.343secs
3. Lewis Hamilton (Mercedes) +13.858secs
4. Alexander Albon (Red Bull) +59.537secs
5. Carlos Sainz (McLaren) +69.101secs
6. Daniel Ricciardo (Renault) +1 lap
7. Charles Leclerc (Ferrari) +1 lap [received 15-second time penalty]
8. Pierre Gasly (Toro Rosso) +1 lap
9. Sergio Perez (Racing Point) +1 lap
10. Nico Hulkenberg (Renault) +1 lap

DRIVER STANDINGS

1. Lewis Hamilton (Mercedes) 338
2. Valtteri Bottas (Mercedes) 274 (-64)
3. Charles Leclerc (Ferrari) 221 (-117)
4. Max Verstappen (Red Bull) 212 (-126)
5. Sebastian Vettel (Ferrari) 212 (-126)

CONSTRUCTOR STANDINGS

1. Mercedes 612
2. Ferrari 433 (-179)
3. Red Bull 323 (-289)
4. McLaren 111 (-501)
5. Renault 77 (-535)

WHAT'S NEXT?

There are just four races remaining in the 2019 season, with the Mexican Grand Prix - which Verstappen has won in each of the past two years - next in two weeks' time.