Frank Abbott of Lakewood Country Club birdied the first extra hole to defeat John Stacey of Army Navy, and Peter Jacobi of Army Navy beat Tom Flory of Prince Georges, 2 and 1, yesterday at Army Navy to gain today's 36-hole final for the Washington Metropolitan Golf Association men's amateur championship.

In the quarterfinal, played earlier yesterday at the Arlington course, two former champions, Anthony (Perky) Cullinane of Columbia and Gill FitzHugh of Army Navy were eliminated in the tournament formerly known as the District Golf Association Amateur.

Cullinane, 1960 and 1976 winner, lost to Stacey, 2 and 1. FitzHugh, the winner in 1973, was beaten by Abbott, 3 and 2.

In the other quarterfinals, Robert Rehman of Indian Spring dropped out of competition with a knee injury and defaulted to Flory, and Jacobi defeated Richard Bowen of Evergreen Country Club, 4 and 3.

In the Abbott-Stacey semifinal, the lead see-sawed back and forth until the 11th hole when Abbott pulled even. The golfers remained even through the 18th hole and started over on the par-5 first hole. There, Abbott won when Stacey missed a two-foot putt.

On that hole, Abbott's drive came to rest on a steep downhill slope leaving him a difficult downhill shot to reach the green 150 yards away. But his nine-iron shot came to rest only a few feet from the green and he then chipped the ball to within 1 1/2 feet of the pin. He made his birdie putt after Stacey missed his.

In the Jacobi-Flory semifinal Flory led by one hole after the first nine, but Jacobi won the 10th hole and then birdied the 13th and the 15th hole to go 2 up.