Tonight Earnie Shavers squares off against Muhammad Ali in a World Heavyweight Championship fight at Madison Square Garden. Challenger Shavers predicts an easy victory over the reigning champion.

Shavers, considerably more talented in pugilistic pursuits than poetry, says, "Ali is an old 35 and he can't run from age. He is going to be the one surprised, not me, because I have never been in better shape."

It's no secret that Ali has not trained hard in the last six weeks. The champ sparred little and frequently strayed from his Deer Lake, Pa., training camp. Instead of road work, Ali walked the streets of New York City in support of mayoral candidate Mario Cuomo.

Meanwhile in the midst of the cornfields and surrounding woods at Turkana Farms in Calcutta, Ohio, Shavers trained in seclusion like a man possessed. Each day, driven by trainer Frank Lucca, Shavers ran five miles around the fields in the morning and sparred, hit the bags, and jumped rope in the afternoon.

Between sessions, Shavers would walk in the woods with an axe and while chopping trees chant, "If I cut off the head, the body must die."

To make a gym, Shavers cleaned the bales of hay out of the barn and set up a ring and bags. Around the ring several wooden chairs filled up the space not required by tractor equipment.

Two banners stretched across the dark, wooden interior. One read, "Ali Must Fall." The other proclaimed, "Earnie Shavers, Heavyweight Champ."

But the sign on the white-washed barn door was the strongest symbol of Shaver's determination and confidence. The sign listed the "all-time hardest heavyweight punchers." Number one was Shavers: 52 knockouts in 54 wins.

In the number ten spot, after names like Marciano, Louis, Dempsey, and Frazier, came not a name, but the words "And Guess Who's Last?"

Tonight Ali needs no introduction. But most fight fans see Shavers, with his shaved head and bearded face, as another nobody with whom Ali toys around to make easy bucks ($3.5 million for Ali, $300,000 for Shavers) and to satisfy demands that the champ defend his crown.

Shavers must give most of the credit for any recognition he has received to Ali. Ali made Shavers's glazed head nationally famous by rubbing pictures of the challenger's head on television and chiding him as "The Acorn."

The 33-year-old Shavers did not throw his first competitive punch until he was 23, when he came off the General Motors assembly line to win the National Amateur title.

Tonight, after eight years of looking for fights on two continents and being avoided by the "name" fighters, the crown is there for the taking. Lucca said, "Someone was always telling us to beat one more guy but nobody would fight us. Foreman refused us, Norton said he hoped he would never fight Earnie. Earnie was too dangerous."

Shavers displayed his ferocious fists in the afternoon sparring sessions in the barn. To soften the impact of his punches so he would not disable or dismember his sparring partners Shavers had to don special 20-oz. gloves.

Only one heavyweight was in camp to provide hard contact work for Shavers but a bevy of light heavies enabled the challenger to improve his speed and footwork for the shuffling Ali.