As Broadway restaurateur Vincent Sardi Jr., 64, and producer Ira Ashley, 65, walked away from seedy Times Square late one night, they looked like an easy enough mark. But when two muggers in their 20s attacked the pair, Sardi wrested the seven-inch boning knife from one of the startled assailants and flipped him to the ground. "It seemed so ridiculous at the time that I practically started laughing," concedes Sardi, a former wrestler at Columbia and a member of the New York City mounted police auxiliary. "I'm not sure I'd do it again." In any case, the two muggers fled, only to be caught within the hour.

The neighborhood may have deteriorated, but not the clientele of the bistro called Sardi's, which began its long run overlooking Shubert Alley in 1921. Paul Newman, Joanne Woodward and their kids come in for family meals. John Travolta, a regular since his days on Broadway in Grease, shows up when he's in town, as do Liza Minnelli, Jack Lemmon, Warren Beatty and Elizabeth Taylor. "My family has had birthday and wedding parties at Sardi's for years," allows Carol Channing, who was attending Bennington College when she first visited in the 1940s. "I plan on having my funeral there."

Until now Sardi has been somewhat leery about branching far beyond the Manhattan landmark founded by his Italian immigrant parents, Vincent Sr. and Eugenia. When Vincent Jr. became fearful that two Houston investors were about to misuse the name, he broke off their tentative partnership and filed suit. Now he is negotiating with another impresario, Art Swires, to establish a Sardi's in that city. Why there? "Houston has a wonderful symphony and regional theater," explains Sardi. "Not to mention loads of oil money." If that works, future Sardi's will follow in London and Los Angeles.

Wherever he expands, however, Vincent Jr. is hung up on Broadway. He still recalls the traditional opening night parties when producers, backers and casts of shows like My Sister Eileen and My Fair Lady sweated out New York critics. He remembers how in the '20s his father extended credit to up-and-comers like James Cagney. It was a non-showbiz patron, however, who most impressed young Sardi. "Helen Keller used to come in all the time," he recalls. "She'd run her hands over my face and then chat with me through her teacher, Anne Sullivan."

Originally Vincent Jr. wanted out of the family trade. He worked his way through college behind his father's cash register and cigar stand, all the while intent on becoming a doctor. But he sold his chemistry textbook so that he'd have enough money for the junior prom and wound up flunking the course. He switched to business administration, graduating in 1937. Two years later he married Carolyn Euiler and eventually saw combat with the Marines in the Pacific in World War II. After he got back, Sardi divorced Euiler and married actress Adelle Rasey in 1947.

By the following year Vincent Jr. had raised enough capital to buy his father out, and Sardi's has flourished at a time when old competitors like Lindy's and Dinty Moore's have gone under. "Vincent is from the old school of restaurant owners," declares Elaine Kaufman, proprietor of uptown rival Elaine's. "I go to him whenever I have problems. Sardi's has what almost nothing else has in this business—staying power." One factor may be that, unlike Elaine's, Sardi's is remarkably unsnobby, and non-stars and even tourists are made to feel at home.

That doesn't mean they will be seated downstairs or join the 600 caricatures that line the walls—a Sardi's trademark since Miriam Hopkins first posed in 1929. Only a handful—including Woody Allen, Elizabeth Ashley and Robert Duvall—dared turn Sardi down flat. The ever proper Charlton Heston also declined because he felt he didn't belong, having never starred on Broadway. Maureen Stapleton posed for the artist Don Bevan, but the portrait disappeared. The culprit soon confessed: It was Stapleton, who hated the drawing so much she burned it. Equally ignominious was the fate of contentious producer David Merrick. Actress Anna Maria Alberghetti took his caricature home and hung it where she felt it belonged—over her toilet.

Some of those tempestuous types should make Sardi look forward to the day when, like his father, he can sell the business to his four adopted kids, "and they can have the satisfaction of working for it like I did." Daughter Tabitha, 26, and her husband, Doug Ricketts, will probably preside over the red velvet rope in New York. Paul, 24, already works for the old man as assistant manager and is likely to run any West Coast operation. David, 22, is studying acting at New York's Ithaca College, and Jenifer, 20, is a disc jockey near the family's summer home in Sugarbush, Vt. Sardi's Japanese foster child, Etsko Tazaki, 31, is a concert pianist who just toured with the Tokyo Symphony.

Split from his second wife since 1975, Sardi is increasingly immersed in his extracurricular passions. He patrols Central Park or the theater district with the mounted police several nights a month. An oceanography buff, he traveled last March to the breeding grounds of the gray whale off the Baja peninsula. He is also investigating "aquaculture"—undersea farming. Then there's another sort of Sardi expedition under way. "I was happy as a bachelor until about a year ago," admits Vincent. "But all that stuff about it being the glamorous life is bunk. Now I'm looking."