FOR the second time in three weeks, Amos Mansdorf has been handed the task of facing the world's number one player. After his 7-6 (7-1), 7-6 (7-5) victory over sixth-seeded New Zealander Brett Steven in the Hongkong Salem Open quarter-finals yesterday, Israeli Mansdorf plays Pete Sampras in the semi-finals today. Two weeks ago in Osaka, Japan, Mansdorf lined up against the then world number one, Jim Courier, in the semi-finals - and stunned Courier with a 7-5, 7-6 victory. It was a result which played a part in the American losing his world number one ranking the following week. Mansdorf, the 27-year-old fourth seed, is now ranked at number 30 in the world but obviously still capable of beating the best. ''I do my best every match and sometimes that's good enough to beat the top players,'' said Mansdorf, after his two-hour three-minute battle against Steven under a burning Victoria Park Centre Court sun. ''They are better players but I think I can beat them from time to time when I play well.'' Mansdorf, who reached a career-high 18th place in the world during his 10 years on the tour, makes up for his lack of height and power with his speed about the court and his touch. And he needed all his court craft and agility yesterday to hold off the 23-year-old Steven, who had proved his staying power with a three-set victory over Tommy Ho in the previous round. An early break in the first-set tie-break put Mansdorf in control and there was no way back for Steven after he slipped behind 4-1. Leading 5-3 in the second set, Mansdorf had victory in his grasp when he raced to 40-0 on his serve, only to lose three match points and the game. Steven, athletic and aggressive at the net, saved two more match points in winning the next game to level the score at 5-5. Mansdorf eventually won through on his sixth match point, in the tie-break. Mansdorf added: I was very disappointed with how I played a couple of the match points but the worst thing that could happen was that I could lose the first set. ''He was hitting some great shots and I didn't think there was any way he could keep it going, even if I lost the set.'' It was all-action stuff and both players were applauded off court. At one point during the tense finale, Mansdorf put his racquet under his arm to clap a winning backhand on the run from Steven to level the second set 6-6. Mansdorf had not been all smiles during the match, though, and vented his frustration at officials over a couple of close line calls which went against him. ''I tried to laugh because I was getting so annoyed,'' he explained. ''Things were not going my way at certain times so I was trying to smile. I could not finish the match and I felt really hot but then I got a second wind towards the end. ''All that can happen is that I lose the match. I do not like it but I am not going to die because of it.'' Of all the semi-finalists in Hongkong today, no-one has more experience of the place than Mansdorf. He won the Asian Junior Championship in Hongkong in 1983 and is making his fifth appearance in a professional event in the territory. His official prize money is near the US$2 million mark and the last of his five titles was won in 1990.