Gary Marlowe of Woodmont won the 16th and 17th holes and halved the final one to beat four-time champion Marty West of Columbia, one up, in a semifinal match of the 60th Maryland Amateur golf tournament today at Green Spring Valley.

Marlowe will play Butch Clemmens of Country Club of Maryland in Sunday's 36-hole final starting at 9 a.m. Clemmens, the club champion at Maryland, edged two-time Maryland Amateur titlist Dave King of Bethesda in 19 holes in the other semifinal.

"It's always great to beat your idol in amateur golf," Marlowe said.

In the morning quarterfinals, Clemmens eliminated Perky Cullinane of Columbia, 4 and 3; King used four birdies to beat Tony Ciconte of Columbia, 2 and 1; West eased past Frank Bart of Hillendale, 4 and 2; and Marlowe chipped into the cup for eagle and a 2-up lead on the 16th hole and went on to defeat Chuck Ebner of Country Club of Maryland, 3 and 1.

That set up the match between West and Marlowe, who as a 19-year-old in 1978 was the youngest ever to win the Maryland Open. West, a Walker Cupper who has played in several Masters and U.S. Opens, was seeking his third straight Maryland Amateur title.

West won the first hole with an "up and down" par, and the third hole when Marlowe's second shot landed six inches out of bounds.

Four times Marlowe evened the match. Trailing by one hole on the par-5 16th hole, Marlowe boomed a drive down the middle, hit the green in two shots and two-putted for a birdie to square the match the final time.

The 17th hole, also a par 5, was pivotal. West's tee shot and second shot both found sand. His third shot went left of the green.

Marlowe hit the green in three shots. West chipped his fourth shot onto the green, 25 feet past the hole, two-putted for bogey and Marlowe went one up with par.

On the par-3 18th hole Marlowe hit an eight-iron over the green into a sand trap. West hit onto the green, 20 feet, from the cup. Marlowe blasted out to two feet from the hole. West's birdie putt rimmed the cup and stayed out. Marlowe ended the match with his tap-in par.

Marlowe felt he was lucky to win after hitting out of bounds on two holes and into a hazard on another. "Giving away holes to Marty is like signing your own death warrant," he said.