Fernando Alonso took his and Renault's second shock victory in succession in the Japanese Grand Prix, as title contenders Felipe Massa and Lewis Hamilton finished only eighth and 12th after a series of controversial early incidents.
Both Hamilton (McLaren) and Massa (Ferrari) were delayed by drive-through penalties - the Briton for forcing Kimi Raikkonen wide at the start, and Massa for pushing his title rival into a spin shortly afterwards.
Robert Kubica kept himself in title contention by finishing second for BMW, fending off Ferrari's Kimi Raikkonen.
Hamilton made a slow start and was behind Raikkonen going into Turn 1, where the McLaren dived down the inside with a tyre-smoking move that took not only Hamilton and Raikkonen wide onto the run-off, but also caused their teammates Heikki Kovalainen and Massa to go off in avoidance.
That allowed Kubica and Alonso to slip into first and second ahead of the recovering Kovalainen, while Massa, Hamilton and Raikkonen fell back into the traffic.
On the next lap Massa ran wide into the Turn 10 chicane, allowing Hamilton to slip past and into fifth place, but the Ferrari fought back across the kerbs at the second part of the corner, punting Hamilton into a spin.
Both Hamilton and Massa would later receive drive-through penalties for their respective aggressive moves, consigning the title contenders to unproductive afternoons in the midfield.
At the front, Kubica held a narrow lead over Alonso and Kovalainen through the first stint, with Raikkonen swiftly hacking through the field and back up to fourth, then closing right in on the closely-matched top three.
But at the first stops Alonso managed to leapfrog Kubica and take the lead, and was able to charge away at the front.
Kovalainen's shot at victory ended at the same time, as his McLaren suffered what the Finn believed to be an engine failure.
By the time Alonso came in for his final stop on lap 43, he had established a 13-second lead over Kubica and an 18-second advantage over Raikkonen, and although both his pursuers were running several laps longer, neither was able to get anywhere near the flying Renault.
Alonso duly pulled away again after pitting, taking another comfortable victory that demonstrated Renault's huge improvements in recent weeks.
Raikkonen picked up his pace significantly prior to his second stop and was able to rejoin just metres behind Kubica. The pair then commenced a spectacular battle for second, running wheel to wheel into the first corner several times in the closing laps.
As they battled, Nelson Piquet closed in after a superb drive from 12th in the second Renault. A good start and very long stints allowed the under-pressure Brazilian to come through the field, and as Kubica and Raikkonen lost time fighting with each other, Piquet moved into podium contention.
Ultimately Piquet dropped back when he ran wide at Turn 5 in the closing laps, while Kubica managed to edge clear of Raikkonen as the Ferrari's tyres faded.
Jarno Trulli took fifth for home team Toyota, losing out to Piquet at the last stops, but his teammate Timo Glock was an early retirement with suspension damage from the first lap incidents.
Toro Rosso got both cars into the points, with Sebastien Bourdais and Sebastian Vettel coming home sixth and seventh, ahead of the flying Massa, who at least reduced Hamilton's lead to six points.
Massa managed to salvage a point despite spinning when he banged wheels with Bourdais as the Toro Rosso rejoined following its final pitstop - an incident that will be investigated by the stewards after the race.
The Ferrari survived that tangle and produced a series of late passes to claim eighth, with Red Bull's Mark Webber his final target. The Australian had driven well on a one-stop strategy, but couldn't fend off Massa at the end.
BMW's Nick Heidfeld also used a one-stop plan to progress to 10th, ahead of Nico Rosberg (Williams) and the delayed Hamilton, who had pitted and taken on heavy fuel immediately after his tangle with Massa. This strategy failed to pay off, as although he was rapidly catching Massa in the middle of the race, he lacked the pace to make progress during his long final stint.
The sole Japanese driver in the field, Kazuki Nakajima, saw his first home race ruined at the start, when he lost his front wing on David Coulthard's Red Bull as it veered across his path after a dramatic suspension breakage. Coulthard, who suspected his suspension had been weakened in first corner wheel-banging, slammed into the barriers but was unhurt.
PROVISIONAL RACE RESULTS The Japanese Grand Prix Mount Fuji, Japan; 67 laps; 305.416km; Weather: Cloudy, dry. Classified: Pos Driver Team Time 1. Alonso Renault (B) 1h30:21.892 2. Kubica BMW Sauber (B) + 5.283 3. Raikkonen Ferrari (B) + 6.400 4. Piquet Renault (B) + 20.570 5. Trulli Toyota (B) + 23.767 6. Bourdais Toro Rosso-Ferrari (B) + 34.085 7. Vettel Toro Rosso-Ferrari (B) + 39.207 8. Massa Ferrari (B) + 46.158 9. Webber Red Bull-Renault (B) + 50.811 10. Heidfeld BMW Sauber (B) + 54.120 11. Rosberg Williams-Toyota (B) + 1:02.096 12. Hamilton McLaren-Mercedes (B) + 1:18.900 13. Barrichello Honda (B) + 1 lap 14. Button Honda (B) + 1 lap 15. Nakajima Williams-Toyota (B) + 1 lap Fastest lap: Massa, 1:18.426 Not classified/retirements: Driver Team On lap Fisichella Force India-Ferrari (B) 22 Kovalainen McLaren-Mercedes (B) 17 Sutil Force India-Ferrari (B) 9 Glock Toyota (B) 7 Coulthard Red Bull-Renault (B) 1 World Championship standings, round 16: Drivers: Constructors: 1. Hamilton 84 1. Ferrari 141 2. Massa 78 2. McLaren-Mercedes 135 3. Kubica 72 3. BMW Sauber 128 4. Raikkonen 63 4. Renault 66 5. Heidfeld 56 5. Toyota 50 6. Kovalainen 51 6. Toro Rosso-Ferrari 36 7. Alonso 48 7. Red Bull-Renault 28 8. Trulli 30 8. Williams-Toyota 26 9. Vettel 29 9. Honda 14 10. Glock 20 11. Webber 20 12. Piquet 18 13. Rosberg 17 14. Barrichello 11 15. Nakajima 9 16. Coulthard 8 17. Bourdais 7 18. Button 3 All timing unofficial