Affirmed and Alydar went barnstorming yesterday for the first time. They brought their thrill-a-second show from New York to Laurel Race Course - and 15,361 area fans were treated to one of the greatest stretch duels in the history of Maryland racing.

The margin of victory was a neck at the end of the 1 1/16 miles of the $144,650 Futurity Stakes. Affirmed prevailed, thus confirming his narrow victories over the Calumet Farm colt in Saratoga's Hopeful and the Belmont Futurity and clinching an Eclipse Award as the nation's champion 2-year-old.

But there was plenty of glory for both performers. They ran their fourth quarter-mile in :24 2/5, with Affirmed on the outside and narrowly in control. Alydar never quit fighting. He carried the famous devil's red and blue silks so honorably in defeat that winning trainer Laz Barrera later was prompted to say:

"What a shame. What a pity.That two colts like this shoud come along at the same time. There is never a disgrace when one of them loses, no matter which one it is. These are two great 2-year-olds, and it looks like it's their future to keep coming at each other again and again."

Barrera was alluding to next spring's Triple Crown series for 3-year-olds. Affirmed will go to California this winter as the early favorite for the '78 Kentucky Derby. Alydar will ship to Florida as the strong second choice for the Churchill Downs classic. Neither will race again this fall.

"Our worry today was not to get hit with a hammer in the back of the neck," Barrera said. Friday morning, John Veitch, Alydar's trainer, had observed that "the way to beat Affrimed is to sneak up on him and hit him over the head. You don't want to have to dog him and try to wear him down."

Alydar's strong finishing kick defeated Affirmed in the recent Champagne Mile at Belmont, forcing a sixth meeting between the two arch rivals, even though the score stood at 3-2 in Affirmed's favor.

Yesterday, in the Laurel Futurity, Jorge Velasquez had no chance aboard Alydar to deliver a knockout blow. Young Steve Cauthen had Affirmed positioned perfectly from the start, on the outside. Affirmed is a little quicker and a trifle more tractable than Alydar, and Cauthen made the most of these qualities.

"We wanted to be on the outside; to have Alydar inside us," Barrera remarked. "That way we could see him. In the Champagne, when we lost, we were inside Alydar and between horses when Alydar made his run on the outside. By the time Affirmed saw him, it was over."

Star De Naskra set the early pace of :24 and :48 4/5. Affirmed ran second early but soon was joined by Alydar. Valasquez had no option but to drive between horses when he shot into the lead through six furlongs in 1:13 3/5. At this point, both colts picked up the tempo as they began a head-and-head battle that lasted for more than a quarter of a mile.

Affirmed pushed his head in front leaving the eighth pole. "Right then," Cauthen said later, "I knew we had Alydar. I wasn't sure before that. I wasn't sure how much Alydar had left. But this was quite a race. These are two really genuine horses."

Valasquez and Veitch offered no excuses.None were needed.

Affirmed's final time, over a dead racing strip, was 1:44 1/5. Harbor View Farm's chestnut son of Exclusive Native paid $4.80 straight and $5.60 with Alydar in the exacta. Alydar was 2 to 5: Affirmed 7 to 5.

Star De Naskra took third place, 10 lengths behind Alydar and 27 lengths ahead of Argento, the trailer. Hidden Rythm was scratched.

Barrera, asked to compare Affirmed with Bold Forbes, his 1976 Kentucky Derby winner, replied, "This colt is easier to rate.