Sebastien Vettel took a commanding third win in a row for Red Bull, vaulting the German into the championship lead.
The race became an endurance test for the Pirelli rubber, with both Red Bulls coming home on heavily-worn boots.
Practice and Qualifying
Red Bull had a good set of practice sessions, with both Vettel and Webber doing well on Friday and Vettel getting more track time on Saturday than his Australian teammate.
Despite falling foul of an electrical problem in Free Practice 3, Webber took a surprise pole position, the 200th for a Renault-powered Formula 1 car. Vettel was close behind with Mercedes-bound Lewis Hamilton third.
Raikkonen split the two Ferraris, Alonso fourth and Massa sixth while Grosjean, under pressure to keep his nose clean, was seventh.
Jenson Button was foiled by a set of yellow flags in Q2 for Ricciardo's stricken Toro Rosso, failing to make it into Q3 by just 0.05 seconds. Ricciardo ended the session 16th but was demoted to 21st after a gearbox change.
Webber got a poor start and was easily passed by Vettel. The Ferrari of Alonso then pressured the Red Bull driver. The two teammates fought hard and fair through the first few corners, but Vettel prevailed.
Button was wiped out by Kobayashi's torpedo-like move on the McLaren driver, almost tearing the Briton's right front wheel from the suspension.
The Sauber driver, and last week's hero and eventual retirement, got a drive through penalty for taking out both Button and Rosberg with the same move.
Rosberg's parked Mercedes, despite being in a gap in the fence, forced Race Control to keep DRS deactivated until lap 9, when the car was lifted clear.
Senna got a good start from his perennial poor starting position, making up five places. Daniel Ricciardo also got a good start, making up six places to fifteenth.
By the time the DRS was activated, Vettel had eked out a two-second gap from Webber, who in turn had just over a second in hand against Alonso.
Michael Schumacher was in the mix early, pulling a terrific pass on Paul di Resta. The Scot had passed him under DRS, the first such pass of the race, but Schumacher used his experience to re-pass at turn four, a trick many drivers would attempt through the afternoon.
Despite talk from Pirelli of a one stop race, Hamilton pitted on lap 14, with a gaggle of cars following him in to discard the less-fancied super-softs.
Webber pitted on lap 14, in front of Massa and Raikkonen. Hamilton's early stop kept him in front of the second Ferrari. Vettel pitted the following lap as did Alonso.
Vettel made it out into clear air but Alonso had to contend with the Sauber of Perez who wasn't interested in giving the championship leader an easy time, staying with the Ferrari all the way down the long straight.
Hamilton took advantage of the battle and passed Perez around the outside at the next corner. Massa had a much easier time getting past, his fresh tyres also yielding a fastest lap of the race. His move was more impressive at it turned out he had a rear roll bar failure.
Raikkonen's fresh tyres were a boon, again Perez was the victim as the Mexican stayed out too long on his first set of tyres. He finally stopped on lap 19 and had a longer stop than he might have liked after the super-softs were bolted on.
Massa's re-found form continued as the Ferrari driver attached himself to the back of Hamilton's ailing McLaren. Massa passed the Englishman on lap 21 with DRS and despite having some KERS charge, Hamilton was unable to repass at turn four.
Raikkonen had a go on lap 23 but was robustly defended. A lap later, he passed him at the hairpin but the McLaren driver came back at turn four with KERS, getting back past the Finn.
The battle continued for several laps, the Lotus driver very keen to get past Hamilton and go after the Ferrari of Massa.
Hamilton pitted on lap 27, releasing Raikkonen. He also suffered from a slow stop after the right front proved difficult to secure. The McLaren seemed to be tearing through its tyres, forcing Hamilton into a three stop race.
Mark Webber had to respond to a charging Alonso, reeling off a 1m44s lap. He radioed his Red Bull team asking for more wing at his second stop to prevent his right front locking up under brakes.
Felipe Massa got in on the fastest lap game and started to close on his team leader on lap 29.
Nico Hulkenberg, now widely expected to move to Sauber, was enjoying a great battle with the Lotus of Grosjean as they scrapped it out for sixth and seventh places. Grosjean pitted on lap 32, Hulkenberg a lap later.
They resumed their battle, with Grosjean triumphing over the German.
Webber pitted for the second time on lap 33, leaving him with 22 laps on the soft, prime tyres.
Alonso pitted on lap 35, having gained a few tenths on leader Vettel but he was unable to jump Webber.
A big lock-up from Vettel brought the German into the pits on lap 35. Massa pitted behind him, as did Raikkonen.
Vettel's deteriorating tyres saw his lead over Webber almost halved while Webber stretched the gap back to Alonso.
Nico Hulkenberg pulled off the move of the race on both Grosjean and Hamilton. The Lotus and McLaren drivers were fighting over sixth place at the hairpin.
Hamilton squeezed the Lotus off the track at turn three, but Grosjean cannily stayed behind and attacked at turn four. Hulkenberg held his line around the outside through four and five and ended up in sixth place.
Both the Toro Rossos somehow worked their way into the points, with Ricciardo and Vergne running a second apart in eight and ninth, later swapping places as Ricciardo ran into trouble. The Australian evenutally finished ninth.
"I'm still grateful to be in the points with such a problem, although it's a case of mixed emotions, as it would have been my best result of the season," Ricciardo said.
Hamilton had a quick final stop and bolted on a set of grippy super-softs to take him to the end. He found himself battling the second Toro Rosso of Jean-Eric Vergne, and battle he did with the combative Frenchman.
Hamilton eventually finished tenth after picking up a chunk of astro-turf at turn 13.
The Red Bulls slowed slightly as worried over tyre degradation set in. Vettel's race engineer, Rocky, was becoming ever more frantic about the German's tyre wear, trying to slow him ever more as the laps ticked by.
Vettel ended the race 8.2 seconds ahead of his teammate who was in turn another five seconds ahead of Alonso. A very fast Felipe Massa came fourth.
Raikkonen's eventful race in an upgraded Lotus saw him come home fifth, Hulkenberg a terrific sixth.
Sebastien Vettel now leads the world championship by six points, an unthinkable situation just a few weeks ago, while both Button and Hamilton must surely be fading from contention.
Webber was pleased with his return to the podium, albeit a little perplexed with his slow start.
"I was on pole but the start wasn't sensational. I will have to look into why but the initial getaway wasn't great. After that it was neck and neck along the back straight but Seb got away," said Webber.
It's now a two animal race - the Red Bull and the Prancing Horse.
Formula 1 returns in two weeks time for the Indian Grand Prix in New Delhi.
2012 Korea F1 GP Results
- Vettel - Red Bull-Renault - 1h36:28.651
- Webber - Red Bull-Renault + 8.200
- Alonso - Ferrari + 13.900
- Massa - Ferrari + 20.100
- Raikkonen - Lotus-Renault + 36.700
- Hulkenberg - Force India-Mercedes + 45.300
- Grosjean - Lotus-Renault + 54.800
- Vergne - Toro Rosso-Ferrari + 1:09.500
- Ricciardo - Toro Rosso-Ferrari + 1:11.700
- Hamilton - McLaren-Mercedes + 1:19.600
- Perez - Sauber-Ferrari + 1:20.000
- Di Resta - Force India-Mercedes + 1:24.400
- Schumacher - Mercedes + 1:29.200
- Maldonado - Williams-Renault + 1:34.900
- Senna - Williams-Renault + 1:36.900
- Petrov - Caterham-Renault + 1 lap
- Kovalainen - Caterham-Renault + 1 lap
- Glock - Marussia-Cosworth + 1 lap
- Pic - Marussia-Cosworth + 2 lap2
- Karthikeyan - HRT-Cosworth + 2 laps
De la Rosa - HRT-Cosworth
Kobayashi - Sauber-Ferrari
Rosberg - Mercedes
Button - McLaren-Mercedes