Not since Walter Cronkite played on-air matchmaker by engineering a meeting between Egypt's Anwar Sadat and Israel's Menachem Begin had a network anchorman so deftly united two people for one common purpose. This time the go-between was Bob Costas, host of NBC's NFL '85 pre-game show, and the prize was not Middle East peace, but marriage.

Prior to the Thanksgiving Day game between the New York Jets and Detroit Lions, Costas' fellow sportscaster Ahmad Rashad, 36 and nervous, surprised everyone with an on-air proposal to Phylicia Ayers-Allen, late 30s, who plays Bill Cosby's wife on The Cosby Show. The startled Costas, who joked that he felt like Chuck Woolery of Love Connection, promised Rashad that the intrepid NFL '85 TV staff would bring Ayers-Allen to the Rockefeller Center studio to deliver her answer at half-time. (She was in town broadcasting the Macy's Thanksgiving Day Parade.) The NBC switchboard lit up, and even the show's staff was stunned, although Rashad had asked for extra airtime that morning. "I thought it was going to be an announcement, something like it was a happy occasion because he was going to marry Phylicia," insists Costas. "It was the proposal that surprised us."

Explained Rashad, a former all-pro with the Minnesota Vikings: "A lot of people [propose] at dinner, and a lot hire those planes with the banners. I figured that if I really loved this lady, I would have no problem proposing to her in front of all those people [an estimated 40 million] watching on TV." And if she had declined? "It probably would have been like the movie Network," he says. "I would have told everybody to stay tuned 'cause at the end of the show I'm going to blow my brains out." He needn't have worried. A giggly Ayers-Allen said yes at halftime. "I couldn't talk," she recalls, insisting she didn't know the proposal was looming. "Anytime something very great happens to me, I can't speak."

Right now the two are in that mushy, post-engagement afterglow, and it's pretty hard to get solid facts out of them. No wedding date has been set, although Rashad says it will be soon. O.J. Simpson will be best man; maid of honor is yet to be determined. Cosby, who introduced the two about a year ago, may give the bride away, although the bride's 12-year-old son, William, is in contention. "My son says Bill can be the ring bearer," she reports. They will probably continue living in New York. And there will be no shortage of jocks at the wedding: Sister Debbie (Fame) Allen's husband is Norm Nixon of pro basketball's L.A. Clippers, and another Rashad pal is John McEnroe.

Both Ayers-Allen and Rashad have been to the altar before. She was married to a New York dentist and later to former Village People lead singer Victor Willis. Says Rashad, who was married and has three children (ages 8 to 15): "I had an aunt who married four or five times. She told me you have to just keep going until you get it right."

It was Rashad who asked Cosby for the introduction. Cosby, says Ayers-Allen, told her his friend Rashad was looking for a nice young lady. She had never heard of the guy. "I said, 'To do what with?' Bill said, 'To take to dinner.' " He escorted her to the People's Choice Awards in Hollywood and so began their dating game.

Both are back at their respective jobs. She is wearing a diamond ring from Rashad—given in private the day after Thanksgiving. Rest assured, NFL '85 will keep you up-to-date on the nuptials.