Pastor Maldonado will start from pole position for the Spanish Grand Prix after Lewis Hamilton was excluded from qualifying for not returning to the pits after setting his best lap.
Hamilton's McLaren was found to not have had enough fuel on board to comply with the rules that demand a car returns to the pits under its own power after qualifying with enough petrol for a one-litre sample to be provided to the FIA.
Only under circumstances of 'force majeure' are drivers allowed to stop on that slowing down lap - and stopping deliberately because there is not enough fuel to finish the tour and supply that sample is not acceptable.
Following a meeting with the stewards at the Spanish Grand Prix, McLaren was informed that the 'technical' problem that it suggested was the reason for Hamilton being told to stop was not enough grounds to justify its action.
The team explained that not enough fuel had been put into the car ahead of the final qualifying lap - which the FIA did not agree was enough reason for 'force majeure'
As a result, the stewards ruled that Hamilton be excluded from qualifying, but would be allowed to start from the back of the grid.
"The stewards received a report from the Race Director which stated that during post-qualifying scrutineering a sample of fuel was required from car 4, however, the car failed to return to the pits under its own power as required under Article 6.6.2 of the FIA Formula One Technical Regulations," said the stewards in a statement.
"The Stewards heard from the team representative Mr Sam Michael who stated that the car stopped on the circuit for reasons of force majeure. A team member had put an insufficient quantity of fuel into the car thereby resulting in the car having to be stopped on the circuit in order to be able to provide the required amount for sampling purposes.
"As the amount of fuel put into the car is under the complete control of the Competitor the Stewards cannot accept this as a case of force majeure.
"The Stewards determine that this is a breach of Article 6.6.2 of the FIA Formula One Technical Regulations and the Competitor is accordingly excluded from the results of the Qualifying Session. The Competitor is however allowed to start the race from the back of the grid."
The result means that Maldonado will start ahead of Fernando Alonso for Sunday's race.
Speaking before being informed of the penalty, Hamilton reckoned that in the event of a penalty he could still deliver good race pace.
"Looking at our long runs, I think our long runs were not too bad," he said. "The option tyre was not spectacular with the set-up we had, but we have made some changes so it should be better in that sense.
"The long run on the prime was very good, but then again so was it with the guys just behind me. Overtaking here is very, very tough as it has showed in previous years, but we do have DRS.
"I would hope we can overtake but I would doubt it - but I would do everything I could to move forwards.
"Definitely the guy in front, the top two or three, generally have an easier job because they have a lot clearer air. But we will give it our all and we hope with improved pit stops as well we hope we can make steps forward."
Revised Spanish GP grid:
1. Pastor Maldonado Williams-Renault
2. Fernando Alonso Ferrari
3. Romain Grosjean Lotus-Renault
4. Kimi Raikkonen Lotus-Renault
5. Sergio Perez Sauber-Ferrari
6. Nico Rosberg Mercedes
7. Sebastian Vettel Red Bull-Renault
8. Michael Schumacher Mercedes
9. Kamui Kobayashi Sauber-Ferrari
10. Jenson Button McLaren-Mercedes
11. Mark Webber Red Bull-Renault
12. Paul di Resta Force India-Mercedes
13. Nico Hulkenberg Force India-Mercedes
14. Jean-Eric Vergne Toro Rosso-Ferrari
15. Daniel Ricciardo Toro Rosso-Ferrari
16. Felipe Massa Ferrari
17. Bruno Senna Williams-Renault
18. Vitaly Petrov Caterham-Renault
19. Heikki Kovalainen Caterham-Renault
20. Charles Pic Marussia-Cosworth
21. Timo Glock Marussia-Cosworth
22. Pedro de la Rosa HRT-Cosworth
23. Narain Karthikeyan HRT-Cosworth
24. Lewis Hamilton McLaren-Mercedes