The forgotten man of the Masters golf tournament going into Sunday's final round is John Mahaffey, the 1978 PGA champion, who shared the best round today (69, three under par) with Bob Gilder.

Mahaffey, with a 54-hole total of 212, is tied with Bruce Lietzke for fourth place, three strokes behind leader Tom Watson. Mahaffey finished his round (birdies at the fifth, eighth and ninth holes, bogey at No. 10, birdie at 13) and came into the press interview room at just the time Watson was overtaking Jack Nicklaus for the lead. He was virtually ignored.

"I read that I was the most boring guy in here, and now I believe it," he said, noting that most reporters were watching a television monitor rather than listening to him recount his round. "I wish we had a TV set out on the course, too. I'd have liked to watch this myself."

There were no questions for Mahaffey, who completed the shortest "interview" in Masters history and departed, muttering, "Gee, I'm glad I wasn't on the Carson show."

Last year's champion, Severiano Ballesteros, who shot 78 and 76 the first two days and failed to make the cut, played golf today at the Augusta County Club, across town from Augusta National, and watched the third round on television with friends in the clubhouse. He will stay through Sunday to take part in the traditional closing ceremonies, in which the defending champion presents the winner's green coat to the new Master.