It took Sampras 4 hours and 5 minutes of tense tennis against the fittest man in the game. But Sampras, the No. 12 seed and a high school dropout from Rancho Palos Verde, Calif., figures he's still years ahead of where he expected to be.
"I thought I'd be somewhere in my 20s before this happened," Sampras, 19, said after his stunning victory. "I really don't think I know where I am yet."
McEnroe followed last night with an impressive 6-1, 6-4, 6-4 win over 21- year-old David Wheaton of Excelsior, Minn. It took McEnroe only 2:14 against an inexperienced and nervous opponent. But McEnroe needs to save every second he can because he's wasted so many years.
After spending most of the last five years sidelined with injuries and burnout, McEnroe has given himself 18 months to "use it or lose it," he has said. "This is very exciting," he said last night. "And unexpected."
McEnroe will meet Sampras on Saturday in one men's semifinal. The other will pit the winners of today's quarterfinals: No. 2 seed Boris Becker vs. No. 9 Aaron Krickstein; and No. 4 Andre Agassi against unseeded Andrei Cherkasov.
For McEnroe, it will be his first Open semifinal appearance since 1985.
Against Wheaton, who is ranked No. 44 in the world, he had an easy workout. McEnroe, ranked only No. 20 and unseeded here for the first time in 13 years, lost only 13 points on his serve.
"I'd seen some of his other matches," Wheaton said, "and I didn't think he was serving that well. Tonight, he was."
McEnroe said he wanted to get off to a fast start. He did, getting the first service break in the first game for a 3-1 lead.
"I knew he'd be tired after playing a five-set doubles match (Tuesday), so I wanted to get him down early," McEnroe said.
Lendl, 30, who had been in the finals here the last eight years, could not do the same. And perhaps it was his own fault. Once in a while, Lendl invites a young pro to his Greenwich, Conn., estate. Lendl gets a practice partner, the player gets lessons from a champion.
In December, it was Sampras, who has big, floppy ears, a big, goofy grin and a big, bopping serve. He spent 10 days with Lendl.
"He had me on the bike like 20 miles a day. He had me running. He taught me that you work until you can't walk home. He's a true professional," Sampras said.
Yesterday, when Lendl, a three-time champion here, expected Sampras to fade in the fifth set, the teenager kept crushing 120-mile-an-hour serves.
In that set, Lendl played one loose service game, the fourth, and was broken when Sampras hit a bullet forehand winner right down the line.
The lead stood up, and when McEnroe won his match, the United States was guaranteed its first Open finalist since 1985, when McEnroe lost to Lendl.
Sampras is long, lean and supple. It looks as if he is all ligament and no bone as he winds up his lanky body to serve.
And make no mistake, Sampras' game hinges on the serve. Against Lendl, he boomed 24 service aces. He varied the pace and placement like a veteran. He had Lendl, the wiliest and steadiest of pros, lunging right and left and finally twirling his racket like a baton, then throwing it in the air in disgust.
"When he serves like that," Lendl said, "there isn't much you can do. He is very talented, but his game right now is very much based on his serve."
The serve was the big weapon in the tiebreak, when Wheaton served an ace and four service winners. But Lendl, who had been up a break and serving for the set, figured he shouldn't have been in the tiebreak.
"I felt I should have won the second set for sure," Lendl said. "It was definitely in my hand, and I didn't take advantage of it."
Lendl said he was disappointed but not surprised at the loss. He came into the tournament not seeded No. 1 for the first time since 1985 mostly because, he said, "I spent all my time preparing for the grass at Wimbledon. I never found the timing on my groundstrokes after that."
Seedings in parentheses.
Quarterfinals: Pete Sampras (12), Ranchos Palos Verdes, Calif., def. Ivan Lendl (3), Czechoslovakia, 6-4, 7-6 (7-4), 3-6, 4-6, 6-2. John McEnroe, Cove Neck, N.Y., def. David Wheaton, Excelsior, Minn., 6-1, 6-4, 6-4.
Quarterfinals: Brian Garrow, Los Altos Hills, Calif., and Sven Salumaa, Huntington, N.Y., def. Andrew Castle, Britain, and Roger Smith, Bahamas, 6-3, 7-5, 5-7, 3-6, 6-3. Pieter Aldrich and Danie Visser (2), South Africa, def. Guy Forget, France, and Jakob Hlasek (7), Switzerland, 7-6 (7-2), 2-6, 3-6, 7-6 (7-4), 6-4.
Quarterfinals: Steffi Graf (1), West Germany, def. Jana Novotna (12), Czechoslovakia, 6-3, 6-1. Arantxa Sanchez Vicario (6), Spain, def. Zina Garrison (4), Houston, 6-2, 6-2.
Third Round: Natalia Medvedeva and Leila Meskhi (14), Soviet Union, def. Patty Fendick, Sacramento, Calif., and Zina Garrison (7), Houston, default.