SAO PAULO, Oct 17 (Reuters) - A frustrated and angry Jenson Button on Saturday braced for the race of his life after qualifying only 14th for a Brazilian Grand Prix he had hoped would crown him champion.

"It makes tomorrow very interesting," the subdued Briton told reporters at Interlagos after a marathon, rain-delayed qualifying session. "It is going to have to be a hell of a race from me, and I don't want to just be picking up a couple of points.

"I want a much better result than that, so I am going to be fighting tomorrow," he said.

Button has a 14-point championship lead with two races remaining but his closest rival, Brawn team mate Rubens Barrichello, will start on pole in front of his home crowd.

Red Bull's Sebastian Vettel, the third man in the title battle but two points behind Barrichello, qualified 16th.

Button said he had struggled with the car in the second phase of qualifying after lowering the rear tyre pressures to combat the aquaplaning on the greasy surface.

"It was like we didn't have a front wing on the car," explained the Briton.

"I am very disappointed to be down where I am. Vettel is behind me, but Rubens is on pole. So it was a terrible qualifying and very frustrating."

The 29-year-old made his emotions evident when asked whether he and his team mate had the same tyre pressures in the second stint.

"I don't know. You will have to ask the engineers. I haven't asked that question yet, I have been too pissed off to ask any serious questions. But we will run through the information tonight," he said.

After a day of torrential rain, thunder and lightning that made visibility poor and conditions hazardous, Button hoped for dry conditions on Sunday.

"It is obviously very difficult to see where you are in the wet. It is difficult to overtake because of the spray, especially when there is a lot of spray because the Tarmac here gives a lot of spray," he said.

"That is why it is so frustrating that I am so far back because I enjoy the wet, and we have been good in the wet this weekend. So it's very frustrating.

"But in the dry I know that we have good straight-line speed, so that will help us quite a bit. Also the cars in front of us are more competitive in the wet than in the dry," he added.

"There are quite a few people within the top 10 or in front of us, top 13, who will not have the pace that we have. In the dry I think we will have good possibilities to overtake."