By Mark Trevelyan
ROSA KHUTOR, Russia (Reuters) - Defending downhill champion Didier Defago of Switzerland acknowledged he had work to do after posting a modest 26th place in Thursday's first training session at the Sochi Winter Olympics, but insisted that "nothing is impossible".
Defago, a surprise winner in Vancouver four years ago, will need another big upset if he is to retain his title on Sunday.
But the veteran has shown flashes of form this season - notably with a World Cup super-G win less than two weeks ago in Kitzbuehel, Austria - and made clear he is not writing off his chances.
At 36, he and American Bode Miller are the oldest men in the men's downhill. But while Miller topped the standings in Thursday's first run, Defago was well down the 61-man field, trailing him by 2.44 seconds.
"It's physically very hard," he told reporters after the first session on the 3,495 metre downhill course, which took place on hard snow in bright sunshine.
"I think everyone is feeling it a bit in their legs. We need to keep something in reserve for Sunday."
While naming Miller, Norwegian Aksel Lund Svindal and his compatriot Patrick Kueng as favourites, Defago said 'there could always be a surprise'.
He said the course - with an 'aggressive' upper section and a hard, icy middle stage - was one that suited his style.
"I feel good ... Nothing's impossible. I'll have to fight. There are two or three key stretches in my mind that are the key ones and I need to work on those tomorrow."
(Editing by Ed Osmond)