Ali and Frazier. Chris and Martina. Bird and Magic. By persevering through a long, meritorious rivalry, champions can take the extra step, to legends.

It could have been that way for Greg Foster and Renaldo Nehemiah. Although Skeets dominated their races, in their youth the hurdlers indicated they would have the kind of magical rivalry that elevates both competitors. For example, in Zurich in 1981, Foster ran the second-fastest 110-meter hurdles ever, 13.03 seconds, but lost to Nehemiah's world record 12.93. Skeets was 22, Foster barely 23. They were full with promise.

But Nehemiah quit track for the NFL, leaving Foster at the top by default, in a sense cheating Foster of his certification of greatness. In ensuing years, Foster won the only transcendent track meets in a decade sullied with Olympic boycotts -- the world championships of 1983 in Helsinki, and 1987 in Rome. Still, Nehemiah wasn't there to validate the triumphs. Even though Nehemiah hurriedly returned to track last winter, and Foster beat him every time they raced, some insist The Real Nehemiah disappeared during the layoff, never to resurface.

"To be perfectly frank with you, I told Renaldo he should have sat out the year," Foster said, explaining how Nehemiah "gave guys who shouldn't touch him a chance to beat him." Foster made a sour face. Like they say in the deodorant ads: Never let them see you sweat.

As to the notion that Nehemiah's absence has deprived him of his just due, Foster conceded that having Nehemiah to race against "certainly makes it a lot easier to train." They're cut from the same cloth, cocky and loquacious. Aiming at a January indoor meet in Foster's back yard, L.A., Nehemiah came back talking like he'd never been away; 4 1/2 years' worth of paragraphs like corn popping on a gas stove. "For weeks, all I heard him say was how he'd basically destroy Gregory Foster. He said the layoff didn't mean a thing. It really gave me incentive." Before the race Foster told an L.A. sportscaster, "One of us, me or Nehemiah, will shatter the indoor record." That night, Foster chainsawed it from 7.47 to 7.36.

Nehemiah clearly brings out the best in him, and though they've never been pals, Foster volunteers, "We're closer." But now, the shoe is on the other foot. "I think I can do it without him. Right now he needs me a heck of a lot more than I need him." Whatever longing Foster may have suffered for becoming No. 1 only after Nehemiah's departure is gone. "I might have felt that way had he not come back talking. But he said the years didn't matter. He said he could still do it. That wipes away the years he was gone." Tilting his head back in satisfaction, Foster said, "As far as I'm concerned he was here all the time."

Foster was in town yesterday in advance of the Mobil Grand Prix indoor meet at George Mason. He is one of the best-known names in track and, at 29, one of the oldest. He'll be 30 in Seoul. For a sprinter, that's George Burns.

Actually, Foster's role model is another L.A. antique, Kareem Abdul-Jabbar, a curious choice since basketball is a team sport. "But when he's got the ball in his hand," Foster pointed out, "it's him by himself."

Foster doesn't know Abdul-Jabbar. It's admiration from afar. "He's why I've never looked at age as a factor," Foster said. "He's 40, and he's better than anyone; he can have the worst game of his life, and still score 30 points. He's been a professional 18 years. I'm out of school six years. The way I look at it, I've got 12 to go." Of his goals, Foster said, "I still haven't run my best time yet. Just because I ran 13-flat doesn't mean I can't run faster."

How much faster?

"I think I can go 12.8."

Should he do it in Seoul, Foster would gain the two prizes that have so far evaded his grasp: the outdoor record and an Olympic gold medal. He got a silver in 1984. Roger Kingdom, apparently a one-race wonder, hit the wire first, after Foster hesitated off the blocks, anticipating a false start. Foster, like Carl Lewis and Edwin Moses, was an alleged mortal lock for gold in Los Angeles; he hadn't lost an outdoor race in three years. "No way in the world I should've lost. I made a terrible mistake at the start," Foster said, adding, "I'm very proud of winning a silver, but I went out there to win gold."

Seoul figures to be his last chance, Abdul-Jabbar's inspiration notwithstanding. That context underscores the poignancy when Foster talks of the condition under which he would not go. Two years ago Foster's mother, two aunts, a cousin, and his namesake nephew, 5-year-old Greg, died from injuries sustained in an automobile accident. They were 20 minutes from Foster's parents' home in Chicago, on their way to Mississippi to visit family, when a hit-and-run driver in a shattering act of recklessness ripped into their car, exploding it. Since then, surviving family members -- Greg, his father, his brothers and sister -- have been especially connected.

"I want to go to the Olympics, but I won't jeopardize my family by going over," Foster said, referring to the concerns for safety amid the political instability in South Korea. "I don't want anyone in this family losing anyone more in this family. I won't risk it. Right now they want me to win the gold, but if something happens, if my family gets nervous and tells me they're not comfortable with me going, that's it, I don't go." Foster's voice was strong with resolve, and his eyes were dry as he said, "We've already been to enough funerals to last a lifetime."