Beating Rafael Nadal on clay is the ultimate challenge, but that may have already become mission impossible for his opponent Dominic Thiem, even before Sunday's French Open final gets underway. Seeking a record-extending 12th title at Roland Garros, where he has an intimidating 92-2 record since 2005, Nadal has had the ideal preparation for Sunday's showdown, beating arch-rival Roger Federer in straight sets on Friday before enjoying a rest day. Austrian fourth seed Thiem, his victim in last year's final, has enjoyed none of those advantages, needing two weather-disrupted days and five sets to get rid of world number one Novak Djokovic in the other semifinal. Thiem, who has become part of the Roland Garros furniture with his fourth last-four appearance in a row, risks being mentally drained when he steps onto Court Philippe Chatrier, Nadal's back-lawn. "The physical part is one thing, and the mental part is another thing," his coach Nicolas Massu told reporters after his protege's semi-final spanned 24 hours. "But when you are in this world... you have to be prepared for everything." Thiem won his last match on clay against second-seed Nadal, but that was the best of three sets. They have met on three previous occasions at Roland Garros and Nadal has won all three encounters in straight sets, including a 6-4, 6-3, 6-2, in last year's final. After winning his first five-set match here, a fired-up Thiem refused to complain about the schedule after his coach was told there was no chance the final would be put back to Monday to accommodate the Austrian. "I'm full of adrenaline, of course, still from today's match, and also I will have that tomorrow," he said. "So I'm not going to be tired. It's all going to come after the tournament. So I'm ready to leave all or everything what I have out on the court tomorrow." So will Nadal, who is on the brink of an 18th major title, which would put him only two shy of Federer's record and make him the only player to have won a slam 12 times. Thiem, who has never made it to the final at another Grand Slam, is looking to become the first Austrian to win a major since Thomas Muster lifted the Musketeers Cup at the French Open in 1995. Should he fail — which seems likely — the 25-year-old Thiem will be back. "I think it's really important that I go into the match with the belief to win," he said. "Of course it's a big dream for me to win that match tomorrow, to win this title. But I also have it in my head that if it does not happen tomorrow — which can happen easily because of the opponent on the other side of the net — I don't make myself too much pressure." — Reuters