Prince Seran broke open the 57th running of the Virginia Gold Cup at the next-to-last fence today and romped home by four lengths over Art Dom, with Tennessee Graham's pair of Man of Rythm and Boca Bird third and fourth, respectively.

Early leader Hoolee was next with Cookin' n Lookin' rounding out the six finishers of the original field of nine. No horse fell victim to any of the 22 fences, but Pidou II, Prayful Rullah and Old Ralph pulled up along the four-mile route.

"We planned to lay behind," said Paul Sloan, the Ashville, Tenn., lawyer who has ridden the John Neal 8-year-old throughout its successful career, "I thought they'd go out as the race went on . . . However, I got a little worried about John Bosley on Art Dom . . . He gave us a run when I finally made my move."

A crowd of close to 20,000 saw Sloan keep Prince Seran off the early pace set by Hoolee, and then Art Dom. The latter, who had run second to Navy Davy in the 1978 Gold Cup, led from the sixth fence through the 19th and was running strongly as they went behind the hill.

As they came back into view at the 20th fence it was Prince Seran on top by a length, then Art Dom and Man of Rythm.

Prince Seran had finished third last year some 10 lengths behind the winner, Juggernaut II, but had given away 10 pounds. The Prince Siam gelding was the Midwest timber champion last year and two weeks ago won the Kentucky Hunt Cup.

Prince Seran's time of 8:56 over a fast course was six seconds slower than Juggernaut II's winning time last year, but only the fourth time in the past 10 years that a winner had cracked nine minutes. The unofficial record for the race is Annual Meeting's 8:27 2/5 in 1971.

It also marked the seventh year that a non-Virginia horse had won the Old Dominion's premier steeplechase. The last Virginia winner was Chapel Street in 1975. It must also be noted that it was the first time in the race's history that a horse from Tennessee had won the big prize.