ELMONT, N.Y., OCT. 27 -- Unbridled received a daring ride from Pat Day and reestablished himself as a contender for horse of the year as he rallied through a tenuous opening to win the $3 million Breeders' Cup Classic today at Belmont Park.

Unbridled, who had not won a stakes race since his Kentucky Derby victory in May, pierced a gap between Thirty Six Red and Ibn Bey with a sixteenth-mile left to win the world's richest race by a length.

Ibn Bey, an English-based colt who had never raced on dirt, took second by a length over Thirty Six Red, a 29-1 shot. Lively One rallied late but finished a nose behind Thirty Six Red.

"It would have been difficult to maneuver around them," Day said. "Unbridled is not the most agile individual. Once I saw the opening I was fixed on going through it."

Unbridled paid $15.20 to win as an entry with Home At Last.

Post position and New York's prohibition of Lasix were central issues preceding the Classic, but Unbridled de-emphasized them. He had the far outside post (14) and didn't race with the anti-bleeding medication he normally receives.

With the 1 1/4-mile race beginning on the clubhouse turn, Unbridled was fanned wide as he entered the backstretch. But he lost precious little ground thereafter. With his mount trailing the field, Day was able to steer Unbridled toward the rail on the backstretch, and from there he waited.

Thirty Six Red maintained his lead despite a fast half-mile of 45 4/5 seconds, but well into the far turn a group of horses was encroaching, favored Rhythm among them. None sustained momentum, and Thirty Six Red straightened for home with nearly a two-length lead over Ibn Bey. Unbridled was advancing on the rail.

Richard Quinn angled Ibn Bey outside for the stretch run, and his mount slowly began to gain on Thirty Six Red, ridden by Mike Smith. Just when Ibn Bey drew even with a half-furlong left, Unbridled went charging between them, a risky move considering Smith was whipping left-handed and Quinn right-handed. He got through cleanly and won his fourth race of the year in 2:02 1/5.

The victory, worth $1,350,000, pushed Unbridled's yearly total to $3,718,149, the most by any thoroughbred in 1990. Trainer Carl Nafzger said before the race the 3-year-old colt owned by Frances Genter would race again in 1991 after wintering in Florida.

Turf: No Arc de Triomphe starter had won a Breeders' Cup race -- and 14 had tried -- until In The Wings wore down With Approval to take the $2 million race by a half-length.

In The Wings, a French colt who was fourth in Europe's most prestigious race three weeks ago, also gave U.S. jockey Gary Stevens his first Breeders' Cup win.

With Approval was two lengths in front entering the stretch. In The Wings then advanced between horses and made a wider run into the lane.

On a good course, he traveled 1 1/2 miles in 2:29 3/5 and became the fourth winning favorite of the program. Runner-up With Approval ended 1 1/2 lengths ahead of El Senor.

Mile: Having retired and served a jail sentence, British jockey Lester Piggott came back to ride Royal Academy to a late-gaining victory over Itsallgreektome, a 36-1 shot.

Piggott, 54, had been out of racing nearly five years -- one spent in prison for tax evasion -- before he resumed riding two weeks ago. Trainer Vincent O'Brien supported the European legend by giving him the mount on Royal Academy while others scoffed -- until the bay colt came charging home.

Royal Academy left the gate awkwardly from Post 1, but Piggott used that to his advantage. Clear of the field, he angled Royal Academy off the hedge, gradually threaded horses through the far turn, then brought Royal Academy three-wide into the stretch.

Itsallgreektome, who's based in California, wore down Expensive Decision on the front end, but as he began to pull away Royal Academy pushed past far on the outside. He took the lead four strides from the wire and won by a head in 1:35 1/5, paying $7.60.

Juvenile Fillies: Meadow Star had the 2-year-old filly title secured before this race, and she lost no supporters with a five-length victory over Private Treasure. At 1-5 odds, she was the strongest favorite in Breeders' Cup history.

Jockey Jose Santos had gone down in a spill in the previous race and said he had pain in his back and leg on his way to the paddock. A few minutes later, he directed the unbeaten Meadow Star to her seventh victory of the year.

The LeRoy Jolley-trained filly pulled away through the lane under Santos's persistent right hand and passed the wire in 1:44 for the

1 1/16 miles. Private Treasure overtook Dance Smartly late to get second by a length.

Juvenile: Fly So Free, with Santos aboard, gave credence to his convincing Champagne Stakes victory with a three-length triumph over upset-minded Take Me Out, in 1:43 2/5 for 1 1/16 miles.