ELMONT, N.Y., JUNE 9 -- The question that dominated Belmont Park all week was this: Could Unbridled run well without the drug Lasix?

Today the Kentucky Derby winner gave an emphatic and disheartening answer to the question: No. Unbridled struggled home a badly beaten fourth, as the Irish-based Go And Go ran away with the 122nd Belmont Stakes.

The winner gave a superb performance, running 1 1/2 miles in the fast time of 2:27 1/5 and winning by 8 1/4 lengths over the early pacesetter, Thirty Six Red. Even so, this race will be remembered most for Unbridled's failure, and surely will intensify the already heated national debate about whether Lasix should be allowed.

It also will prompt further discussion of the rules governing the Triple Crown bonus, for Unbridled earned $1 million despite his mediocre showing, more than twice what Go And Go received.

Unbridled had been treated with Lasix in the Derby and in his second-place Preakness finish, but couldn't use it in New York, the one state where it is prohibited. Bettors here displayed their worries that the colt might be a drug-dependent animal by sending him to the post as a tepid even-money favorite -- double the price he might have been if medication were not an issue.

The crowd of 50,123 threw heavy support to Thirty Six Red, who figured to be the dominant speed horse in this race -- and he was, taking the lead after a few strides. Go And Go broke sharply, and his Irish jockey, Michael Kinane, angled to the rail, within easy striking distance. He was going to have a perfect, ground-saving trip all the way. "I was traveling very sweet," Kinane said.

Thirty Six Red covered the first half-mile in 48 seconds when Baron De Vaux, the Maryland-based long shot, rushed up inside him to duel for the lead. Go And Go was stalking them. But as the field reached the final turn, Unbridled launched his move on the outside, and looked for a few strides as if he was going to deliver the same powerful acceleration that had carried him to victory at Churchill Downs.

Unbridled surged past Go And Go into third place -- but stayed there for only a few strides. He couldn't sustain his move, and when Kinane looked at him, he said: "I knew Unbridled was beat. And I had loads of horse." As Unbridled faltered on the turn, Go And Go pulled away from him again, and took aim on the two horses in front of him.

Thirty Six Red had finally shaken off Baron De Vaux, and jockey Mike Smith said: "Everything was going good. My horse really dug in." But when the Irish colt swooped outside him, the leader couldn't resist. Go And Go ran the final quarter-mile in :25 2/5 and drew away with every stride. Thirty Six Red finished two lengths in front of Baron De Vaux, with Unbridled another 2 1/2 lengths back in fourth place. Then came Yonder, Land Rush, Video Ranger, Hawaiian Pass and Country Day.

Go And Go earned $411,600 of the $686,000 purse for his owner-breeder, Walter Haefner, a Swiss industrialist.

Go And Go was the unknown quantity in this field, and bettors here had enough respect for him to make him the fourth choice in the wagering at 7 to 1. He had come to the United States last fall for the Laurel Futurity, which was supposed to be run on turf. But when rain forced a transfer of the race to the main track, Go And Go ran anyway, even though he had never competed on a dirt track before. When he won the race in fast time, trainer Dermot Weld had fortuitously discovered the colt's best game.

Weld had been thinking about the Belmont Stakes ever since, and said this week that every move he had made with Go And Go in 1990 had been done with this objective in mind. He did all of his training in Ireland -- the colt was swimming for exercise there as recently as Tuesday -- and came here Wednesday, the type of schedule that has generally proved most effective for European invaders.

Go And Go was exempt from all of the discussions about Lasix, for medication is prohibited in Ireland, as it is in the rest of the racing world outside the United States. But almost as soon as jockey Craig Perret had dismounted for the losing favorite, he was asked about the subject.

"Nothing happened," Perret said, meaning that the colt didn't bleed, which later was confirmed by an endoscopic exam of Unbridled's windpipe. He said trainer Carl Nafzger "took every preparation to have his horse ready for this performance. He showed no wear and tear. He didn't need the Lasix. Now everyone will say he did."

Perret is correct on that point. While there is no way to know whether Unbridled at his best would have beaten Go And Go, he was unable to beat two rivals whom he had trounced by more than 15 lengths in the Derby and the Preakness. And although the jockey theorized that Unbridled lost because he was tired after a long campaign, the racing world will hold the opinion that Lasix was the key to this Belmont.

Horse ................Jockey

Go And Go ....Michael Kinane

Thirty Six Red ...Mike Smith

Baron De Vaux ...Jean Cruguet

Complete Results, Page B13

Copyright 1990, News America Publications Inc.

1 1/2 miles; $1,686,000. Track: Good.

Time: :23 2/5; :48; 1:12 1/5; 1:36 2/5; 2:01 4/5; 2:27 1/5.

Horse...........Jockey...PP... 1/2./... 3/4...Mi...Str....Fin....Odds

Go And Go.......Kinane...2....5 ....3 ..3 ...1 ....1 .....7.50

Thirty Six Red..Smith....1....1 ....1 ..1 ....2 ...2 .....3.70

Baron De Vaux...Cruguet..3....3 ....2 .2 ...3 ....3 ...68.30

Unbridled.......Perret...5....6 ....4 ..4 ....4 ....4 .....1.10

Yonder..........Bailey...8....7 ...6 ..5 ....5 ....5 ....6.30

Land Rush.......Cordero..9....4 ...7 .6 ...6 ....6 ...12.00

Video Ranger....Santos...6....8 ...9...8 ....8 ...7 ....10.30

Hawaiian Pass...Madrid...7....2 ...5 .7 ....7 ...8 ...75.50

Country Day.....Antley...4....9.....8 ..9.....9.....9.....10.10

GO AND GO, $17.00, $6.20, $4.80; THIRTY SIX RED, $4.40, $4.20; BARON DE VAUX, $12.60.

EXACTA (2-1): $98.00

Go And Go, under stout restraint early, moved within easy striking distance along the inside midway along the backstretch, came out from behind the leaders approaching the stretch, caught Thirty Six Red nearing the final furlong and drew off under brisk urging. Thirty Six Red went right to the front along the inside, raced well out from the rail while showing speed into the backstretch, dueled with Baron de Vaux to the stretch but was no match for the winner. Baron De Vaux, sent up along the inside early, headed Thirty Six Red after going 5 1/2 furlongs, dueled with that rival to the stretch while continuing to save ground and tired. Unbridled, never far back while racing outside horses, made a run from the outside at the far turn, but was finished entering the stretch. Yonder, outrun early, moved up while racing wide on the far turn but gave way under pressure. Land Rush tired badly while racing wide. Video Ranger failed to be a serious factor. Hawaiian Pass raced forwardly until near the end of the backstretch and stopped badly. Country Day stumbled badly when caught in close quarters soon after the start and was far back when his rider lost the whip leaving the far turn.