Seattle Slew, continuing his belated bid for Horse of the Year honors, smashed the track record for a mile and one-quarter yesterday at Belmont Park with a four-length triumph in the $166,000 Woodward Stakes.

Drawing away from Nelson Bunker Hunt's well-regarded Exceller through the stretch, Seattle Slew earned first money of $97,800 and became thoroughbred racing's 23rd millionaire. The purse gave the 4-year-old son of Bold Reasoning a career bankroll of $1,075,520 with 13 victories in 15 starts.

Ridden with supreme confidence by Angel Cordero Jr., Seattle Slew coasted in front early, as expected, then won as much the best after his rider rapped him twice with the whip, right-handed, in the drive.

Exceller, with the veteran Bill Shoemaker aboard, finished 6 3/4 lengths ahead of It's Freezing. The latter earned the show money by a nose over Great Contractor, with Wise Philip a remote trailer.

Heavily backed by the majority in a crowd of 27,023, Seattle Slew returned $2.60, $2.10 and $2.10. Exceller, a 19-10 chance, paid $2.20 and $2.10 and It's Freezing 45-1, was $2.10 to show.

Seattle Slew was timed in 2:00, shattering the previous mark of 2:01 4-5 for a mile-and-one-quarter event started on the turn.

The Belmont record for the distance around one turn of the mile-and-one-half track is 1:59 4-5, a mark Seattle Slew would certainly have erased had the Woodward been started in the chute on the backstretch.

Repair work being done on a nearby training track made it necessary for yesterday's event to be started on the clubhouse turn.

Seattle Slew's fractions were :24 4-5, :47 3-5, 1:10 4-5 and 1:35 1/5 with Exceller, usually a late runner, trying to force the pace because there were no other horses in the small field with any early zip.

"He's the greatest horse I've ever been on," Cordero said of Seattle Slew after the race. But Cordero was unhappy because 1978 Triple Crown winner Affirmed was not in yesterday's field.

"I know it takes a great horse to win the Triple Crown," said Cordero, "but I think Horse of the Year should not go automatically to the Triple Crown winner. It should go to the best horse in the country. If I had Affirmed, I would have run him today no matter what the purse was."

Seattle Slew beat Affirmed by three lengths in the recent Marlboro Cup Handicap.

Owner Louis Wolfson and trainer Laz Barrera kep Affirmed out of the Woodward to await the $300,000 Jockey Club Gold Cup, an event Seattle Slew is expected to pass.

Missing from the Woodward was the 8-year-old Forego, which had won the classic four straight years but has been retired to a life of ease on John Ward's farm near Keeneland race track in Lexington, Ky.

Shoemaker, who rode Forego to victory in the Woodward the last two years, said Exceller ran a good race despite the fact that he hadn't run in three months. "The early fractions were slow," said Shoe, "and I know that I moved my horse a little closer than usual. He was running easy but Seattle Slew was going along as he pleased. He's tough horse to beat when he can set those early fractions."

Immediately after the Woodward, the 47-year-old Shoemaker left to board a jet for Paris. He will pilot Hunt's Trillion in today's rich Arc de Triomphe at Longchamp.

The heavy wagering to show on Seattle Slew caused a minus pool of $33,023 at the track and an additional $7,511 at New York's Off Track Betting parlors.A minus pool results when the track and OTB must make up the additional money necessary to pay off the minimum $2.10 to show.