The McLaren drivers have both been moved five places down the Malaysian Grand Prix grid as a punishment for impeding Nick Heidfeld and Fernando Alonso in qualifying.
Heikki Kovalainen and Lewis Hamilton will now start the race from eighth and ninth positions respectively.
The pair had completed their final flying laps of qualifying sooner than usual because the threat of rain encouraged most drivers to take to the track at the earliest opportunity in qualifying.
Keen to conserve fuel for the first stint of the race, they then slowed significantly and cruised back to the pits.
But while they were doing so, other drivers were still on flying laps, and both Heidfeld and Alonso felt they had been obstructed by the cruising McLarens.
After complaints from Heidfeld and Alonso, the stewards summoned Hamilton and Kovalainen to explain their actions, and have now decreed that both should be given a five place penalty.
McLaren does not plan to appeal the decision.
"Car number three (Heidfeld) was impeded in its flying lap due to the fact that car 22 (Hamilton) was travelling at a very slow speed on the racing line," said a stewards' statement, with a second similar statement also issued in respect of Kovalainen.
As a consequence, Jarno Trulli will now start third for Toyota, with both BMWs moving into the top five.
Mark Webber and Fernando Alonso have also been elevated two places to sixth and seventh, ahead of Kovalainen and Hamilton.
With rain a strong possibility for tomorrow's race, the penalty may be less damaging than it would have been in normal circumstances.
It has been raining heavily at Sepang since 3.30pm local time, and the likelihood of changeable weather in the race could give the McLaren drivers more chance to recover than they would have should conditions remain dry.
Revised starting grid:
1. MASSA Ferrari
2. RAIKKONEN Ferrari
3. TRULLI Toyota
4. KUBICA BMW
5. HEIDFELD BMW
6. WEBBER Red Bull
7. ALONSO Renault
8. KOVALAINEN McLaren*
9. HAMILTON McLaren*
10. GLOCK Toyota
11. BUTTON Honda
12. COULTHARD Red Bull
13. PIQUET Renault
14. BARRICHELLO Honda
15. VETTEL Toro Rosso
16. ROSBERG Williams
17. FISICHELLA Force India
18. BOURDAIS Toro Rosso
19. SATO Super Aguri
20. SUTIL Force India
21. DAVIDSON Super Aguri
22. NAKAJIMA Williams**
* penalised 5 places for impeding Heidfeld
** penalised 10 places for Melbourne incident