-- When trainer Robin Graham returned Mr. O'Brien to the turf after nearly a year of dirt racing, she gave the mount to jockey Rick Wilson and watched them score a nine-length victory in the Henry Clark Stakes at Pimlico on Kentucky Derby day.

On May 8, Wilson, 50, who ranks 20th in career wins, suffered severe head and neck injuries in an accident coming out of the Pimlico starting gate in the second race. On Friday, Wilson was upgraded from critical to serious condition at University of Maryland Hospital, and when jockey Ramon Dominguez rode Mr. O'Brien to an upset victory in the Grade II $200,000 Dixie on Saturday afternoon, he paid tribute to the fallen rider.

"This has been a big day for me," said Dominguez, who won three races on the card. "This probably would have been Rick Wilson's mount. I'm happy I could pick up where Rick left off. We're all thinking about him."

The 103-year-old Dixie is the eighth-oldest stakes race in the country and was won by Preakness in 1870 when it was still called the Dinner Party Stakes. The race this year attracted several talented runners, but Mr. O'Brien virtually duplicated the move he made in the one-mile Henry Clark to win the 11/8-mile turf race in a blazing time of 1 minute 46.34 seconds.

"We figured there was plenty of speed in the race," Graham said. "I told the jockey to just let him be wherever he wanted to be early. He relaxed the horse and just waited until the time was right, and the move was timed perfectly. This horse will go whenever you ask him." . . .

The total handle at Pimlico was a record $85,120,667; on the Preakness alone, it was $58,791,406, also a record.

Roundup

In other stakes races on the card:

* Gallorette Handicap: Sitting patiently just off long shot pacesetter Lavender Baby, jockey Jerry Bailey struck coming out of the far turn and drove favorite Ocean Drive to a half-length victory in the 53rd running of the Grade III $100,000 Gallorette for fillies and mares. Film Maker, ridden by Edgar Prado, made a belated charge through the stretch, quickly closing the gap, but ran out of time. The winner ran the 11/16-mile race in a speedy 1:40.85 on the firm, fast turf.

* Hirsch Jacobs Stakes: Laurel Park-based Abbondanza has been a horse with great promise ever since his devastating debut in the mud at Aqueduct in February. The chestnut colt broke through with his first stakes win in three tries for trainer Tim Tullock, winning the $100,000 Hirsch Jacobs for 3-year-olds by a head over late-running Bwana Charlie.

* Woodlawn Stakes: Jockey Richard Migliore looked in trouble, steadied aboard his mount Artie Schiller at the three-eighths pole in a crowded field of 13 horses. Yet, the New York-based jockey rounded a spot inside coming off the turn, eased out in the stretch and drew away with dramatic acceleration to win the turf stakes race for 3-year-olds by 33/4 lengths.

The Belmont Park-based runner has now won four of five turf starts.

* William Donald Schaefer Handicap: Seattle Fitz, a 5-year-old who has run against Peace Rules, Medaglia d'Oro and other top horses, toyed with an overmatched field to win the Grade III $100,000 race for 3-year-olds and up. Rated behind the speed in third place by Migliore, Seattle Fitz put away The Lady's Groom in the stretch to win by 11/2 lengths. Trained by Kiaran McLaughlin in New York, the horse ran the 11/8-mile race in 1:49.43 seconds.

"He was much the best today," said Migliore, who was shaken up Friday in a starting gate at Belmont Park. "I'm pretty beat up today after yesterday, but I'm feeling better every time I win."

* Sir Barton Stakes: Nick Zito's up-and-coming Royal Assault scored by 13/4 lengths in the $100,000 Sir Barton, the consolation prize on the Preakness card for 3-year-olds. Ridden by Hall of Famer Pat Day, Royal Assault came from last to first in the field of eight, putting away Dashboard Drummer in deep stretch to win the 11/16-mile race in 1:45.63.

"I actually toyed with the idea of running this horse in the Preakness," said Zito, who will run Royal Assault in the Belmont. "The Sir Barton has produced a lot of good horses."