Vettel, who could clinch a fourth consecutive drivers’ title this weekend, suffered a Kers power-boost system failure, which proved decisive in his battle for a career 43rd pole position.
Lewis Hamilton will start from third on the grid, just ahead of Lotus’s Romain Grosjean.
He needs to maintain or better that position in tomorrow’s race to keep the title alive, should Vettel win his 35th Grand Prix.
“It’s a great track and we all love driving here. The laps weren’t too bad but you always want a little bit more. It was pretty good,” said Webber, who is quitting F1 this season to switch to driving a Porsche in the endurance racing circuit.
“Sebastian had a problem so a little bit of a hollow result. But happy to be on pole and you’ve got to grab the opportunity when you can.”
Vettel though refused to blame technology for his performance – insisting he was confident all would come good on Sunday.
“The car was phenomenal and you don’t get many days like that when the car feels great and you can really push it to the limit,” he said.
“We did have a problem but I am not a big fan of this, ‘without this, with this’, it is always an unknown.”
Alonso also insisted he had no complaints about his display, in a qualifying session dedicated to the memory of fellow Spaniard and Formula 1 reserve racing driver Maria De Villota – who died from natural causes in Seville on Friday.
“Yesterday was a shock, we do practice, you take the helmet off and they tell you this terrible news, you never expect this, especially with her she fought so much this last year and she was full of life,” he said.
“I’m not surprised with my position, it’s not been a good week but I need to do better in the race obviously.
“I was more or less I was eighth, ninth all weekend so it is not unexpected.”
1. Mark Webber Australia Red Bull-Renault 1m 30.915s
2. Sebastian Vettel Germany Red Bull-Renault 1m 31.089s
3.. Lewis Hamilton Britain Mercedes-Mercedes 1m 31.253s
4. Romain Grosjean France Lotus-Renault 1m 31.365s
5. Felipe Massa Brazil Ferrari-Ferrari 1m 31.378s
6. Nico Rosberg Germany Mercedes-Mercedes 1m 31.397s
7. Nico Hulkenberg Germany Sauber-Ferrari 1m 31.644s
8. Fernando Alonso Spain Ferrari-Ferrari 1m 31.665s
9. Kimi Raikkonen Finland Lotus-Renault 1m 31.684s
11. Sergio Perez Mexico McLaren-Mercedes 1m 31.989s
12. Paul di Resta Britain Force India-Mercedes 1m 31.992s
13. Valtteri Bottas Finland Williams-Renault 1m 32.013s
14. Esteban Gutierrez Mexico Sauber-Ferrari 1m 32.063s
15. Pastor Maldonado Venezuela Williams-Renault 1m 32.093s
16. Daniel Ricciardo Australia Toro Rosso-Ferrari 1m 32.485s
17. Adrian Sutil Germany Force India-Mercedes 1m 32.890s*
18. Jean-Eric Vergne France Toro Rosso-Ferrari 1m 33.357s
19. Max Chilton Britain Marussia-Cosworth 1m 34.320s
20. Charles Pic France Caterham-Renault 1m 34.556s**
21. Giedo van der Garde Holland Caterham-Renault 1m 34.879s
22. Jules Bianchi France Marussia-Cosworth 1m 34.958s**
* denotes driver due to take five-place penalty
** denotes driver due to take ten-place penalty