Cherish your friends, suffer no fools, say what you mean, and do as you please. A little luck helps too.

That's Dr. Fernando Pacheco's prescription for a good life. For him the luck came in 1962, when a young boxer named Cassius Clay walked into the doctor's Miami office complaining of a cold. Ferdie Pacheco became Clay's personal physician and was granted a ringside view of his transformation into heavyweight champion Muhammad Ali.

For 15 years Ali has not fought without Dr. Pacheco's reassuring presence in his corner. His bout this week against Alfredo Evangelista in Landover, Md. will be no exception.

"Ali has everything—size, speed, style, the greatest body God ever blessed a man with," his doctor says. "Next to Ali, Marciano was a dwarf, Joe Louis was slow of foot and couldn't take a right, and Jack Dempsey? Christ, he only weighed 189 pounds at his peak." But as Ali's skills decline with age, Pacheco sounds increasingly worried. After the champion's listless performance against Ken Norton last year, Pacheco told him, "I wish you would quit now. I would be the happiest person in your entourage if you did." (Since 1970, Pacheco reveals, he has given Ali an injection of novocaine in the knuckles before each fight to dull the pain of his punches.)

Pacheco knows the value of membership in Ali's inner circle—"without him I would be nothing but another Miami doctor." But that does not blind him to the champ's weaknesses—particularly of the flesh. "He is a pelvic missionary," Pacheco marvels. "God, the number of broads he's laid in the past few years—he shows up in town and they're waiting for him in the hotel lobby: young, old, beautiful, ugly. He's laid more ugly women than you'd ever believe," Pacheco says. "Ali wants to be liked. He has a great capacity to give and to receive, and it carries over into exchanging bodies. He thinks the woman will remember it all her life."

Even without Ali, Dr. Pacheco, 49, has had an amazing career. A family physician for 20 years in Miami's Cuban and black ghettos (earning more than $100,000 a year in Medicaid and Medicare payments), Pacheco is also an accomplished artist and author. His book Fight Doctor is due this year. He collects military headgear and owns five antique cars, including a 1942 Darrin Packard that was a gift from FDR to the president of Mexico.

Twice married and the father of four, Dr. Pacheco and his wife, Luisita, 34, a professional flamenco dancer, live in a sprawling home in Miami's walled-off Bay Point area. "I've compartmentalized my life," he says of his ability to shift from one world to another.

He grew up in Tampa, where his father managed a pharmaceutical supply company. Young Ferdie's intellectual interests kept him in college for eight years, accumulating biology, chemistry and pharmacy degrees, with a pile of credits left over in English, philosophy and history. His M.D. is from the University of Miami.

Pacheco's fame as a fight doctor (he has worked with eight other world champions besides Ali) will be enhanced this month with the release of the film The Greatest, starring Ali as himself. The doctor will be portrayed by John Marley, who was Ali McGraw's dad in Love Story. The movie skips over Pacheco's most prized gift from his most famous patient. It is a diamond ring inscribed to "Dr. Pachecco." So the name is misspelled? It means all the more to the champ's doc.