Beech Hills' Benji Vaughn Masco, a German shepherd, won the working dog group and then was named best in show yesterday in the 74th National Capital Kennel Club Dog Show at Rosecroft Raceway.

Benji Vaughn Masco, working group champion in the Westminster show in New York in February, was not bothered by the 1,000 spectators. Many of his competitors were.

"He gets turned on by applause and you can really feel him respond to it," Ken Rayner said of the 5-year-old he trains for Mary Ellen and Pat Thomas.

"This was a very tough group, because you are getting the best dogs from all the divisions. But this dog is a competitor, and even though it was a large group (22 dogs), I felt my chances were good for a win going in," Rayner added.

Peggy Adamson, working group judge who awarded Benji Vaughn Masco victory in a recent Philadelphia show, was impressed with the quality of the dogs in the working group, which includes herding and service breeds.

"I know there were at least 10 or 12 dogs that could have won. I really couldn't make any cuts," Adamson said. "But that dog is magnificent and he keeps getting better all the time. He has such personality."

Sulan's Gregorian Chant, a Lhasa apso, was named best among the nonsporting breeds and Mike-Mar's China-Dragon, a Pekingese, won the toy group.

"This is the seventh straight group we've won this year," China-Dragon's owner, Michael Wolf, said. "But it's still very exciting. There were a lot of good dogs and it could have gone either way. I had to use an ice bag to keep him cool . . ."

In the terrier group, Hobbit Hill's 2-year-old Up an' Adam, a Sealyham, won. Drummont's Tasty Billy, an English setter, claimed the sporting group title. Englandale's Fugitive, an English foxhound, won the hound group.

The show featured 1,947 dogs of 122 breeds.