Apprentice Bryan Antley fell off front-running Big Bay Cruiser a half-furlong before the finish of yesterday's fifth race at Laurel, but the only persons hurt were those who had backed the colt at 70-to-1 odds.

The incident provided a bizarre twist to an unusual story. Antley was riding for Leo Azpurua, a trainer who arrived from the south last week and in his second race at Laurel sent Twice Regal to a nine-length triumph on turf that paid $31.

In yesterday's 1 1/16-mile turf race, Antley took Big Bay Cruiser to the lead, and went ahead by five lengths through the backstretch.

By the 16th-mile pole, the race was his. Social Prospect, the 8-to-5 favorite, was about four lengths back.

Then Antley whipped Big Bay Cruiser left-handed once, then a second time, and the bay colt lurched to the right. "He didn't duck because of the whip," Antley said. "He ducked from something he saw. Something spooked him."

Antley lost his balance and fell off the horse's left side but clung to the reins. Big Bay Cruiser dragged him for a couple of strides before Antley let go and slid on the turf.

At that point, Social Prospect, ridden by Danny Nied, was in position to win. But Social Prospect had to dodge Antley, and the other 10 horses in pursuit also avoided him.

"I couldn't have missed him by more than two inches," Nied said. "When I saw him coming off, I tried to get away from him. But he hung on to the horse, and caused him to start drifting."

As Big Bay Cruiser ran riderless, Kent Desormeaux's Count Twice passed Social Prospect to win by 1 1/2 lengths, and Desormeaux, the nation's leading jockey, was en route to his second consecutive five-win day.

For the second straight weekend, a French filly moved to the fore at Laurel. Louise A La Plage, trained by four-time Washington, D.C. International winner Maurice Zilber, found room leaving the far turn and ridden by Dominique Boeuf went on to a five-length victory over favored Fieldy in the $105,125 Chrysanthemum Handicap.

A daughter of His Majesty, Louise A La Plage covered 1 1/8 miles on turf in 1:48 2/5, going the final eighth-mile in :11 4/5. "She was pounds the best," said Boeuf, 19.