Brazil GP, Sao Paulo - Sunday, 1800 BST
Michael Schumacher admitted he faces a daunting task in Sunday's Brazilian Grand Prix after his Ferrari failed in the final part of qualifying.
Ferrari mechanics tried to fix Schumacher's car but to no avail
"It will all be a lot more difficult now," said the 10th-placed German, who had to retire in Japan two weeks ago.
"It's pretty obvious I'm not exactly happy but we had to absorb a technical setback in Suzuka and then one today.
"It's obviously unfortunate that in such short succession this happens in a situation where it was important."
Schumacher, who must win on Sunday to have any hope of retiring with an eighth title, could only watch from the Ferrari garage as team-mate Felipe Massa seized pole position in front of his home crowd at Interlagos.
"We lost fuel pressure, we don't really know why," said Ferrari technical director Ross Brawn after the German failed to complete a timed lap in Saturday's final qualifying session.
I can only try to fight. I will fight and then we will see what happens
"We went to leave the pit lane and the fuel pressure disappeared. There was not much we could do. We need to have a look inside the car and see what happened."
It was the second successive blow for the 37-year-old German.
The German had clawed back into title contention after being 25 points behind Alonso at the end of June, only to write off his chances after the Japanese Grand Prix two weeks ago when engine failure left him trailing Alonso by 10 points.
To seal an eighth world crown, Schumacher must win Sunday's race and hope Alonso finishes below eighth or retires.
Michael's problems are a bit of a bonus, but we are never going to write him off because we know what he can do
"I can only try to fight," he said. "I will fight and then we will see what happens."
"I have no clue as to how the race will develop. It's hard for me to predict something. All I can do is achieve the maximum out of this situation."
But Alonso insisted he would take nothing for granted on Sunday as he closes in on a second drivers' title.
"Michael's problems are a bit of a bonus, but we are never going to write him off because we know what he can do," said the 25-year-old.
"We were looking to be in the top five or six, and then with Michael's problems we gained a place because he was going to be ahead of us, so fourth is very good.
"Being on the first or the second row was almost a dream because we knew qualifying would be the most difficult part, so the race is looking very good and so also is the championship.
"Michael in tenth, that helps me to be a little more relaxed."