Neff McClary of the Country Club of Fairfax became the first Northern Virginian in the 64-year history of the tournament to win the Virginia State Amateur title yesterday.

McClary recorded five birdies on the final 18.

He defeated Bill Sibbick, 21-year-old University of North Carolina senior, 1 up, in 36 holes at Washington Golf and Country Club. It was the first time the tournament had been held in Northern Virginia.

McClary, 33, who with his father owns at Alexandria construction company, finished the tournament the way he started: the hard way. Four of his five matches were not decided until the 18th or last hole. The other went to the 17th.

McClary, a nonstop cigar smoker, was 1 down after the morning round. He squared the match on the fourth hole in the afternoon and went ahead for the first time with a birdie at the fifth hole. But Sibbick, an unflappable golfer, came back on the sixth to even it again.

McClary won the next four holes with two pars and birdies at eight and 10. The next two were halved, making McClary 4 up with six to go.

Then it was Sibbick's turn to rally. He won the 13th and 14th with pars and birdied the 15th, reducing McClary's margin to one.

On the 16th, a 324-yard par four, both were on the green in two with McClary away at 20 feet. He stroked the ball into the cup for a birdie.

Sibbick had the same line and a shorter putt by five feet. He was distracted by the firing of a pistol that started a swimming race in the pool above the green. He went a foot past the hole and McClary was dormie two.

The 17th hole was played on the first hole from a different tee because the 17th green is under repair.

Most golfers throughout the week used an iron off the tee on the 312-yard hole because the fairway is narrow with trees on the right and out-of-bounds on the left.

McClary played it safe with an iron and was 75 yards short of the green. Sibbick went for broke and hit a tremendous drive, the ball landing in the trap. McClary's wedge was over the green and the finished with a bogey. Sibbick got out of the trap nicely and two putted for his par to bring it to one down and one to go.

Both had fine drives that split the fairway on the 18th McClary, the longer man, put the ball 20 feet from the flag, with an uphill putt. Sibbick's second shot went into the trap over the green. He blasted out two feet from the hole but McClary lagged his third shot a foot away and had an easy par to win the match.