As Slew o' Gold and Bates Motel battled through the stretch in the Woodward Stakes--just as they may do again Saturday in the Marlboro Cup--the crescendo began.

By the time the two horses reached the wire in that race three weeks ago, the often-jaded Belmont Park fans were screaming. They were not only reacting to the most exciting thoroughbred race of the year, they were encouraging and hailing their man, Angel Cordero Jr., in one of his finest moments.

Most of the time, Cordero is the jockey New Yorkers love to hate. But on this day he was their champion, defending their honor against another invasion from California.

New Yorkers have been hearing for years about how the racetracks, the horses and the jockeys in the West have become superior to their own. But now Cordero was showing these interlopers who was Numero Uno. On paper, Slew o' Gold didn't figure to have a chance against Bates Motel, but in the early stages of the Woodward, Cordero had outpositioned and outmaneuvered his rival, Terry Lipham. And then, after Bates Motel made his usual powerful move on the turn, Cordero simply outmuscled Lipham.

He whipped Slew o' Gold, he pushed him, he refused to let the colt give an inch of ground to Bates Motel. And when his horse's nose reached the finish wire first, Cordero shot his fist in the air, triumphantly. He knew--and everybody at Belmont Park knew--that he had made the difference.

Including the people with Bates Motel. When trainer John Gosden watched the televised replays of the Woodward, he exclaimed, "He is certainly a strong finisher."

Lipham evidently knew it, too. Despite what New Yorkers may think of him after this one performance, he is respected as one of the most intelligent riders in California, one whose good judgment compensates for what he may lack in raw strength. But he told Gosden he would understand if he wanted to change jockeys for the $400,000 Marlboro Cup.

Gosden did just that, and enlisted Chris McCarron to ride Bates Motel Saturday.

McCarron's credentials will not be confused with those of Terry Lipham. McCarron has been the country's top race-winning rider three of the last 10 years; he has won the Eclipse Award as the country's outstanding jockey. Although he is based in California, he has ridden enough at Belmont Park to know the special demands of the country's only 1 1/2-mile track.

It's a classic confrontation: East vs. West. Slew o' Gold vs. Bates Motel. Cordero vs. McCarron.

The two principals are so formidable that the remainder of the seven horses in the Marlboro are almost irrel.vant. They are Bold Style, Highland Blade, Sing Sing, Deputed Testamony, May Day Eighty, Hyperborean and Gato del Sol.

Gosden says he does fear Gato del Sol, the almost-forgotten winner of the 1982 Kentucky Derby who regained his top form in California this summer. But neither his top form nor anybody else's figures to be good enough to threaten the two colts who ran 1 1/8 miles in a sensational 1:46 3/5 in the Woodward.

In the rematch, Bates Motel seems to have most of the advantages. The jockey change should help him, of course. He has been given a surprisingly charitable 124-pound weight assignment by racing secretary Lenny Hale. And the 1 1/4-mile distance of the Marlboro should favor him.

He scored his most important victory, in the Santa Anita Handicap, at that route, while his arch rival has never won that far. Owner Mickey Taylor said that he thought that distance is "definitely within Slew o' Gold's capabilities," but he also recognized that his colt has only one real edge in this confrontation: "We've got Angel Cordero."