A large broken-plate painting by Julian Schnabel, American's hottest young artist, was auctioned here tonight for $93,500, a record price for a Schnabel, and a triumphant auction debut for the artist.

"Notre Dame" (1979), a hefty work combining big brush strokes and big bits of broken crockery, was one of the key lots in a Sotheby's auction of post-World War II art, which also included the collection of Vincent Melzak, past president of the Corcoran, and other record-setting works by colleagues of Schnabel.

"Notre Dame" was purchased by Anita and Burton Reiner, collectors who live in Bethesda. Anita Reiner, who is an art adviser, was in the room bidding on the picture. She confided in a member of the Sotheby's staff after the sale that she'd always wanted a Schnabel plate painting, but that his dealer, Mary Boone, had always refused to sell her one.

"I've loved his work since I first set eyes on it about four years ago," said Anita Reiner. "I think the price was a little steep, but that's what I had to pay to get one."

Though Schnabel was not at the auction, Boone, was. She had been bidding actively on "Requiem fur Waltraaud (N-Komplex)" (1976), a painting by A.R. Penck, a German colleague of Schnabel's, which brought $35,200.

She refused at first to comment on the Schnabel sale. "I'm going out for Italian food," she said. "No, I'm not particularly pleased with the sale price ."

Boone, who is credited with much of Schnabel's success, had expected the painting to bring more than $100,000. Similar works go for $60,000 in her SoHo gallery, but there is a long list of prospective buyers for the early such as "Notre Dame."

Schnabel, the biggest splash in the art world since Andy Warhol in the 1960s, has enjoyed a phenomenal rise to fame. In less than four years, prices for his works have zoomed from $3,000 to $60,000--and tonight, $93,500. Banking on the attraction of the Schnabel work, Sotheby's positioned it last in the sale.

With more than 1,000 fashionable contemporary art buffs looking on, in addition to bidders hooked up to the room via telephone at the Chicago Art Fair, there was considerable excitement when the Schnabel came up. Nearly everyone sat still as the bidding started at $50,000. It quickly rose to the sale price; a polite round of applause followed.

The Schnabel sale eclipsed the main event: A painting by Jasper Johns, one of American's great living artists, fetched $363,000, a record price at auction for a Johns (his "Three Flags" was sold privately two years ago to the Whitney Museum for $1 million).

The work, "In Memory of My Feelings--Frank O'Hara" (1961), which Johns painted as a tribute to the poet, a friend and supporter of many New York artists in the '50s, also commanded the highest price at tonight's sale.

The rest of the sale, in which $2.5 million worth of art was sold, had some ups and some downs.

The key lot of the Melzak offerings, Kenneth Noland's "Rest" (1958), failed to sell, even though bidding on the work reached $230,000. Apparently Melzak was convinced that "Rest" would break the $300,000 record set last year by another Noland target painting. He wouldn't budge from his position on "Rest" or on Willem de Kooning's "Untitled" (1951), which failed to sell after bidding at $120,000.

Morris Louis' "Pillar of Celebration" (1961), did, however, meet Melzak's expectations, fetching $242,000; as did Noland's "Blue Horizon" (1963), $79,750; and Larry Rivers' "Front and Side Views" (circa 1960), $30,250.

Most of the Melzak collection, which he had acquired when many of the works were new, from the Washington Color School and other artists, has been donated to the Smithsonian. These few remaining works brought $352,000. They had been expected to bring up to $860,000.

Melzak, who was sitting in the second row, sporting an ascot, dark glasses and a tan to match, said after the sale he was "fairly" pleased with the results. Since he retired from the Corcoran in the early '70s, he has been breeding Arabian horses in West Virginia.

Melzak sold these last gems of his collection, he said, because his son, who is a Green Beret, and his daughter, who is a nurse, are not interested in the paintings. "They'd rather have the money," he said.