Mark Webber started from pole but lost the lead to Grosjean, and then his team switched him to a three-stop during the race.
Daniel Ricciardo raced well but fell to thirteenth after a wild pass on Paul di Resta saw him penalised. Read on for how it all went down.
PRACTICE AND QUALIFYING
The Mercedes W04s put on a good show in FP1, with the Red Bulls going 1-2 in FP2.
Backmarkers Bianchi and van der Garde crashed at the Degner curves in FP1, with Bianchi's car out of action for the rest of the weekend. His Marussia team built up the spare for Saturday's action.
Perez damaged his McLaren at Spoon and Maldonado crashed at Degner. Perez would also require his spare chassis for the rest of the weekend.
Adrian Sutil continued to endear himself to his team by crashing in FP3, requiring frantic efforts to fix the car.
Qualifying took place under sunny skies but in blustery conditions. It got a little too hot in the Sauber pit as Esteban Gutierrez's car set itself on fire in the garage. Amazingly, the car went back out minutes later.
Vergne's Toro Rosso set itself on fire out on the track as both rear brakes burst into flame.
Webber out-qualfied Vettel whose final lap appeared to be free of the recurring KERS problem. Vettel would start from P2, Hamilton third.
"I will never forget the first sector today - it is what we strive for, what our profession is for, so it was a real highlight today," said Webber.
Daniel Ricciardo started in sixteenth.
The race started under bright skies, but Charles Pic had a drive-through before even got to the grid. He was found to have run a red light at pit exit on Saturday. Sutil started at the back after a gearbox change.
Grosjean got a monster start, firing past the Red Bulls. Hamilton and Vettel squabbled on the way into turn one, damaging the front wing of Vettel and puncturing Hamilton's right rear tyre. The Mercedes driver pitted while Vettel stayed out.
Both Bianchi and van der Garde fell off the road at turn one, ending their races.
The Saubers had also got a good start, with both of them running strongly in the top ten. Webber settled in behind Grosjean for a few laps, but tried to stay within DRS range.
On lap six, Raikkonen began a concerted effort to pass tenth-placed Jenson Button with a long-shot move at turn one. He got past on the next lap as behind him Ricciardo passed Bottas for thirteenth.
Vettel struggled with his car, running wide in the esses and falling over two seconds behind Webber. Webber was told to save his rear tyres and wait until closer to the pit stops to go after Grosjean.
Hamilton parked the Mercedes on lap 8, while Rosberg went off the road in sympathy at turn one.
By lap 11, Grosjean had created a gap of 2.1 seconds. Webber stopped on lap 12 as did Felipe Massa and Kimi Raikkonen. Grosjean pitted a lap later and he resumed the track ahead of Webber.
Mercedes landed themselves in more trouble by releasing Rosberg from his pit stop in front of Perez. The German had to dodge and nearly clobbered a couple of Lotus mechanics in the process. Rosberg got a drive-through penalty.
Alonso pitted on lap 14 and Vettel came in on lap 15, indicating a two-stop strategy. He returned behind Webber.
Ricciardo was yet to stop on lap 18 and had Nico Hulkenberg interested in his fourth place. Behind Hulkenberg was Massa and Alonso, all being held up by the fading tyres on the Toro Rosso.
Alonso got by Massa on lap 20 with a little help from his DRS and went on to have a crack at Hulkenberg. With Massa, Gutierrez, Raikkonen and Button behind as well, the train behind the Toro Rosso growing ever longer.
Hulkenberg made the move at 130R and Massa almost re-passed Alonso. Then Gutierrez almost capitalised on a Massa mistake at Degner, the Sauber pushing the Ferrari wide in a wheel-banging battle lasting several corners. Massa prevailed and Raikkonen then got past Gutierrez at 130R.
On lap 24, Webber fired-up and took off after Romain Grosjean, cutting his lead to under a second, before taking his second stop rejoining behind teammate Vettel who seemed to be struggling a little, locking up badly into the chicane.
Ricciardo had a heart-stopping moment on his way out of 130R as he passed Paul di Resta. He went wide and on to the dust, just getting back on to the track and making the chicane. He made another pass two laps later on Pastor Maldonado's Williams at turn one. Unfortunately, he received a drive-through for the pass on di Resta.
Grosjean began to struggle with his tyres, with Webber running rampant in third, taking huge chunks away from the Lotus driver. Webber shot past Grosjean as he was stationary in the pits, but with a much greater gap.
Webber needed to keep building, however, as Grosjean would not have to stop again. Vettel was building his own lead over Grosjean to ensure he returned to the track ahead of the Lotus.
Perez must have wondered what he had done wrong before the race as his second stop was marred by a sticking right rear tyre, his second fraught stop.
Another penalty was handed out by the stewards, this time for Felipe Massa speeding in pitlane.
Vettel stopped on lap 37 as his lead to Grosjean fell to under twenty seconds. Vettel took on hard tyres and rejoined behind Romain Grosjean. Webber held a 14-second lead over the Lotus.
Nico Hulkenberg was doing a tremendous job in the Sauber, holding fourth ahead of Raikkonen.
Vettel attacked Grosjean on lap 40 through 130R and the chicane. Grosjean kept the Red Bull at bay but lost out on the straight.
Webber pitted on lap 43 for his final stop and to take on the titanic battle to pass both Grosjean and Vettel to win the race.
Perez's terrible race was dealt another blow on lap 43 with a left-rear puncture. None of the Mexican's troubles were his fault, he had driven well but was hit by Rosberg who was trying to pass.
With nine laps to go, Webber had a 3.6 second gap to Grosjean and a further four to Vettel.
Alonso finally found a way by Hulkenberg on lap 46, taking the German at turn one.
Webber got a DRS tow from Grosjean on lap 47, but the Frenchman blocked robustly, preventing a pass.
After a number of spirited attacks, Webber nailed the pass when both cars had DRS amid a gaggle of backmarkers, but it was too late for the Australian.
Raikkonen got by Sauber's Nico Hulkenberg at the chicane in a typically brave Raikkonen move.
After a scrappy first half of the race and troubled qualifying, Vettel crossed the line. Webber took second, rueing the team's choice to switch him to two stops.
"I asked was it the right thing to do. Seb went a bit longer, but the target for two stops was achievable. I felt we could get to the laps we were looking to get to," Webber said.
"I didn't think the battle was going to be with Seb, [but] it was pretty much done when we didn't do enough damage on the three stop against Seb's pace on two."
Grosjean finished a fighting third, Alonso fourth and Raikkonen fifth. Nico Hulkenberg again scored points for Sauber in sixth. Daniel Ricciardo faded to thirteenth after his penalty.
Formula 1 returns in two weeks for the Indian Grand Prix.
Japan F1 Results
- Sebatian Vettel - Red Bull-Renault 1h37.410s
- Mark Webber - Red Bull-Renault +7.1s
- Romain Grosjean - Lotus-Renault +9.9s
- Fernando Alonso - Ferrari +45.6s
- Kimi Raikkonen - Lotus-Renault +47.3s
- Nico Hulkenberg - Sauber-Ferrari +51.6s
- Esteban Gutierrez - Sauber-Ferrari +1m11.6s
- Nico Rosberg - Mercedes +1m12.0s
- Jenson Button - McLaren-Mercedes +1m20.8s
- Felipe Massa - Ferrari +1m29.2s
- Paul di Resta - Force India-Mercedes +1m38.5s
- Jean-Eric Vergne - Toro Rosso-Ferrari +1 lap
- Daniel Ricciardo - Toro Rosso-Ferrari +1 lap
- Adrian Sutil - Force India-Mercedes +1 lap
- Sergio Perez - McLaren-Mercedes +1 lap
- Pastor Maldonado - Williams-Renault +1 lap
- Valtteri Bottas - Williams-Renault +1 lap
- Charlies Pic - Caterham-Renault +1 lap
- Max Chilton - Marussia-Cosworth +1 lap
- Fastest lap: Mark Webber, 1m34.587s
- Lewis Hamilton - Mercedes - 9
- Giedo van der Garde - Caterham-Renault - 0
- Jules Bianchi - Marussia-Cosworth - 0