Button won last year's race at Suzuka, beating Alonso and Vettel to take the chequered flag.
You can follow all the action as this year's race unfolds below.
8.45amThat brings to an end our coverage of the Japanese Grand Prix. The Championship race is well and truly on after some first-lap drama at Suzuka. Join us next week for the Korean Grand Prix. Until then, take care...
8.41amThe Japanese crowd are chanting "KAMUI! KAMUI! KAMUI!" - he'll be a proud man as he stands on the podium.
8.36amYou can read Matt Domm's report of this race by clicking here.
8.34amVettel's win blows the drivers championship wide open. It's been a grim day for Fernando Alonso.
8.33amMassa finishes second and Kobayashi is third! The Sauber team are absolutely delighted!
8.32amSEBASTIAN VETTEL WINS THE JAPANESE GRAND PRIX!
FINAL LAPButton gets into DRS range but gains little ground on Kobayashi. Meanwhile, Grosjean has retired.
Lap 52Kobayashi is driving well though. Button has used all of his KERS, while the Sauber still has reserves for the final stand. It looks like he can hold on for what would be like a victory in front of his home fans.
Lap 51Button has slashed Kobayashi's lead to just over one second.
Lap 51The race is very stretched a the front, and has become less bunched at the back as the race has worn on.
Lap 50Michael Schumacher, who started way down on the grid, is now trying to pass Ricciardo and get into 10th. Incredible driving.
Lap 49The gap from Vettel to Massa is now 19 seconds.
Lap 48Kobayashi is finding the pace just when he needs it. This is where the battle of the track is on. The Sauber increased its lead by three tenths of a second on the last lap.
Lap 47Button is right on Kobayashi's shoulder now. You just fancy the McLaren man to overtake the home favourite.
Lap 46Vettel looks nailed on for the win, while Massa should finish second barring catastrophes. Button is on for a place on the podium if he can keep up this pace on Kobayashi.
Lap 45Button was half a second faster than Kobayashi in the last lap. These gains are inching him closer to the Sauber.
Lap 44Button is closing the gap on Kobayashi in third. That is developing into an interesting tussle.
Lap 42Senna is trying to take Grosjean on. He's has a couple of bites at him but can't seem to get around the Frenchman. That battle is for 14th.
Lap 39Senna sets the fastest lap of the race on soft tyres.
Lap 38Vettel is now on a new set of hard tyres. He is now around 17 seconds ahead of Massa. Sublime driving by the German.
Lap 37Most drivers are on their second set of hard compounds. Those who aren't are coming in.
Lap 36Button pits for new tyres and is he going to get out in front of Kobayashi... no! The Japanese driver was well away.
Lap 35Karthikeyan is out of the race. His HRT is back in the garage.
Lap 33Hamilton comes out of the pit lane and an immediate battle with Raikkonen ensues! The Lotus and the McLaren go wheel to wheel and it looks like Raikkonen is just beating Hamilton to the curve, but the Englishman stays on the inside line and stays ahead!
Lap 31Perez seems to have taken a bit of responsibility for the mistake that has ended his race. "I braked too late, and the only room I had was on the outside and I spun it," he told Sky Sports News.
Lap 29Vettel is about to lap Petrov. It's been the perfect afternoon for him so far.
Lap 28Vettel has been steadily building on his lead at the front and the gap is nearly 11 seconds now.
Lap 28Plenty of three-car battles for places on the track as well.
Lap 27There hasn't been the same overtaking action that we've become accustomed to in other races this season. It's more of a battle of attrition, making small gains on your opponent and waiting for the right moment to pass.
Lap 22Meanwhile, out in front, Vettel is extending his lead. He is over nine seconds ahead of Massa and looks like he will cut Alonso's lead down to size.
Lap 21It didn;t look like either driver, Hamilton or Perez, did much wrong in that exchange. Perez inched his nose in front of Hamilton but the wheels seemed to touch and spin the Sauber out of control.
Lap 20... and Massa now takes that accolade off Button.
Lap 19Button has posted the fastest lap of the race.
Lap 19Hamilton and Perez comes together! The Sauber looks like it is out of the race!
Lap 19The drivers have all pitted now for fresh tyres. Here's a check on the top 10: Vettel, Massa, Kobayashi, Button, Raikkonen, Hamilton, Perez, Hulkenberg, Maldonado, Webber.
Lap 18Kobayashi gets by Ricciardo on the hairpin! Great move! Button is now having a look at the Australian.
Lap 15Kobayashi comes into the pits for a tyre change and he returns to the track behind Ricciardo in seventh.
Lap 14Perez is on Raikkonen's shoulder. They're battling for fifth place.
Lap 13Suzuka is living upto its reputation of being difficult to overtake.
Lap 11Glum faces all around the Ferrari garage. And no wonder, it's been pretty much the worst start imaginable for them.
Lap 10Vettel goes even faster this lap. Serene driving.
Lap 9The German has over a four-second gap between himself and Kobayashi.
Lap 9Vettel posts the fastest lap of the race. It seems he is in control of proceedings.
Lap 8Hulkenberg is now having a good look at Hamilton. Perez's move on Hamilton was a beauty. Interesting, considering their impeding switch around.
Lap 7Grosjean will incur a 10-second penalty for the collision with Webber.
FORMATION LAPThe cars are off around the track, most on soft compound tyres.
6.53amWe're moments from the formation lap and the teams are making the final adjustments to their machines.
6.51amMaldonado: "It's going to be a tough race for everybody, especially because of the tyres."
6.50amMartin Whitmarsh: "It looks pretty tough [for Hamilton & Button] from here but we're going to be fighting all the way."
6.49amVergne: "Hopefully we can have a better race [than Singapore] and make some early moves."
6.45amRoss Brawn: "Difficult qualifying in the end. Hopefully a few events go our way during the race. We've had safety cars here the last few years so hopefully we can catch that well."
6.43amButton: "It was always going to be disappointing here with the five-place gride penalty, but anything's possible."
6.40amMartin Brundle reminds people that the safety car has been deployed at Suzuka in five of the last seven years. That owes much to the tight bends around the track.
6.38amAlonso currently leads the drivers championship by 29 points ahead of Vettel. Raikkonen, Hamilton, Webber and Button also have designs on the title, but most will tell you that it will be either the Spaniard or the German who will be adding to their two titles.
6.29amThere could be some drama at the final hairpin today. Coming just before the finish line, it ensures that drivers must stay switched on for the entire lap.
6.27amSebastian Vettel and Fernando Alonso have both won this race twice. Jenson Button will attempt to join them with victory today but he faces a tough task. Overtaking at Suzuka is notriously difficult.
6.25amIt's the first time this season that Red Bull have locked out the front row. It looks as though they have put their recent poor form in qualifying behind them.
6.22amGood morning everyone. Welcome to Sports Mole's live coverage of the Japanese Grand Prix.