On a day when his principal rivals were relying on the skills of their veterinarians, blacksmiths and lawyers, Deputed Testamony won the 108th Preakness the old-fashioned way.

Brought into the race in perfect physical condition by trainer Billy Boniface and ridden perfectly by Donald Miller, the Maryland-bred colt scored a 2 3/4-length victory over Desert Wine, with High Honors third. Sunny's Halo, the Kentucky Derby winner, faded to finish a badly beaten sixth.

It was a surprisingly conventional conclusion to a week that had been filled with medical drama and legal maneuvering. Sunny's Halo had been plagued by ringworm. Marfa had to have his hoof patched together after cracking it during a workout. Desert Wine's owners had gone to court so he could be treated with the drug Lasix to prevent him from bleeding.

While all this was happening, Deputed Testamony stayed far out of the limelight, in the tranquility of Boniface's Bonita Farm in Bel Air, Md. He had not been run in the Derby because his trainer wouldn't risk racing him when he was subpar physically. He did not arrive at Pimlico until 12:30 this afternoon, but when he came onto the track, his neck bowed, exuding fitness, he was ready to spring one of the biggest Preakness upsets in years.

The chances of Sunny's Halo were compromised in the first seconds of this race. When Common Sense, the horse next to him in the starting gate, swerved to the right and bumped him, Sunny's Halo had to spot the field a two-length head start. Because of the favorite's difficulties, Desert Wine was able to pop out of the gate and take a clear lead in the run to the first turn. "He broke running," jockey Chris McCarron said, "and then he relaxed as he always does." Miller was content to keep Deputed Testamony fifth on the rail, and he was given plenty of room to maneuver because most of the other riders were avoiding the inside part of the rain-soaked track.

Jockey Eddie Delahoussaye had to hustle Sunny's Halo to get into contention, and midway on the backstretch the Canadian colt finally moved up to challenge Desert Wine. The 71,768 spectators might have momentarily expected the Preakness to turn into a replay of the Derby, when these two horses had battled each other for the last half-mile. But this was not the same Sunny's Halo today.

Longshot Bet Big moved up to challenge the leaders, and appeared as if he were going to fly by them. Then Marfa started to accelerate wide on the turn, and it looked as if the piano wire and the 13 screws in his hoof were going to do their job. But the strongest horse belonged to Miller. Deputed Testamony had been saving ground and--equipped with mud caulks--he was handling the sloppy track efficiently. He had a cluster of horses in front of him, but, Miller said, "I knew a hole would open somewhere." It opened when Desert Wine swung slightly wide entering the stretch and left room on the rail.

Miller, 19, wasn't riding like a jockey who had gotten this assignment by default; Boniface asked him to take the colt only after Laffit Pincay Jr. and Jean-Luc Samyn turned down the job. But nobody could have done any better on the turn than Miller.

"I had to move a little sooner than I wanted," he said, "but I didn't want to get shut off." He drove inside the leader, and Desert Wine's Lasix wasn't enough of a miracle drug for him to withstand the challenge. Deputed Testamony surged to take a clear lead in mid-stretch, and none of the horses behind him was accelerating. He covered the 1 3/16 miles in 1:55 2/5, respectable but not exceptional time.

Deputed Testamony earned $251,200 for Boniface and co-owner Francis Sears of Boston; he went off at 14 to 1 and paid his backers $31, $10 and $6.40. Desert Wine returned $4.80 and $4.20, and fast-finishing High Owners paid $9.60 to show.

If this result was a shock to many, it was not totally surprising to Marylanders who respect the skills of Boniface and Miller and who knew Deputed Testamony had a lot more talent than his pedigree suggested. His sire, Traffic Cop, stands for a $1,000 stud fee; his dam raced in cheap races at Charles Town. Deputed Testamony started his career running for a $25,000 claiming tag at Bowie.

But when the colt ran impressively and lost by a nose in last fall's rich Maryland Juvenile Stakes, Boniface started planning for the Kentucky Derby. His plans appeared to be on schedule when the colt won the Federico Tesio Stakes here in sensational time. But when he went to Keeneland for the Blue Grass Stakes, he ran dismally and Boniface realized afterward that the horse had been suffering from a fever. Deputed Testamony had to skip the Derby and was sent back home to Bonita Farm to recuperate. Then he prepped for the Preakness by winning a minor stake at Keystone last week.

It is safe to assume that Deputed Testamony didn't make his recovery with the aid of wonder drugs; Boniface has been the state's most outspoken spokesman against the modern trend toward so-called "permissive medication." He was so outraged when Desert Wine's owners went to court so their horse could race with drugs that he said he briefly thought about dropping out of the race. But he could savor this Preakness as a triumph for traditional virtues. "Those California boys might have won it court," he said, "but we won out there today."