The world No 1, winner of eight Grand Slam titles, fought out a tense five-set match with Costa who stormed around the court, chasing every ball and conjuring up impossible shots to keep the top seed on the back foot.
Each time Sampras took a set lead, the 10th seed fought back but he could not prevent the American storming through at the end to win 6-3, 6-7, 6-1, 3-6, 6-2. Sampras kept his cool in the closing stages, his serve leading the way. He sent down 23 aces in the match and won almost all his first-service points.
"He's fast, he's good. He's got one of the best backhands I've ever seen," Sampras said of Costa. "On the run, I couldn't believe some of the shots he was getting. Now I've got one day off and then it will be Thomas, which will be a war. We've played each other a number of times and I know what to expect, and he knows what to expect. It's just a matter of who does it better."
Muster once more broke Goran Ivanisevic's Grand Slam hopes, shutting him out in a duel of big hitters. The world No 4 from Croatia, who has yet to win one of the game's four major titles, made a string of unforced errors as he lost 6-4, 6-2, 6-3. He said: "I had a lot of chances I didn't take. And if you don't take those chances, you're gone."
With the roof of Centre Court pulled over for the second day, this time due to torrential rain rather than sun, Muster, the fifth seed, appeared to relish the indoor hardcourt conditions. He played a far smarter game to unnerve Ivanisevic, serving smoothly and wearing his opponent down from the baseline.
The Swiss 16-year-old Martina Hingis breezed into the women's semi-finals with a straight-sets victory over Romania's Irina Spirlea. The fourth seed made a tentative start, dropping her second service game but immediately broke back and was never troubled again, winning 7-5, 6-2 in just 70 minutes. She has yet to drop a set in the tournament.
Hingis then revealed she had fallen off her horse on Tuesday. The fall, she said, "wasn't dangerous at all. My mom was there and she was laughing. Everybody was laughing. Mentally, it just helps you sometimes if you do something else and not just tennis all the time."
Past gymnastics experience helped her roll safely on the grass after she went flying over the horse's head. Then she climbed back on and continued her ride. "I was jumping and the horse didn't jump, and I jumped by myself," said Hingis, explaining her faulty timing, before adding that she will not do any more riding during the tournament, but only because there is not enough time.
There was heartbreak for Belgium's Dominique van Roost, who handed the 14th-seeded American, Mary Joe Fernandez, her first Grand Slam semi-final in four years when she retired hurt in the second set because of a pulled abdominal muscle.
It was a sad end to Belgium's best Grand Slam performance following the defeat of the 16th seed, Sabine Appelmans, on Tuesday. Van Roost said: "A lot of people think Belgium is French. Sometimes you cannot even see the country on the map. I think now they know more about Belgium from the tennis."
Both women's semi-finals take place today, before the first men's semi- final between the world No 2, Michael Chang, and Spain's Carlos Moya.Reuse content