Gary Marlowe, believing he needed to birdie the final hole to force a playoff, sank an 18-inch putt for par and won the 58th Maryland Open Golf Championship yesterday at Manor Country Club.

Marlowe's final-round 73 gave him a 54-hole score of 210, matching par.

Marlowe's victory was set up when Mark Alwin double-bogeyed the 17th and three-putted No. 18. Alwin, a pro at Woodholme, had made up a three-stroke disadvantage to Marlowe and pulled ahead by one earlier in the round.

Starting yesterday's final round of the 54-hole tournament, Marlowe led Marty West of Columbia (137-139) by two, and Alwin and Perky Cullinane, also of Columbia, by three.

Marlowe, a 19-year-old who plays out of Woodmont and competes on the Louisiana State University golf team, played the first nine holes in par 35. For that score, he needed several spectacular second shots to make up for erratic tee-offs.

"Was there a fairway out there?" Marlowe queried after the round. "I'm not sure, because I never found it."

Meanwhile, Alwin completed a birdie on the ninth for a one-under 34 on the turn, and later birdied the pare 4 12th. Marlowe bogeyed both the 152- yard par-3 11th and the par-4 13th to enable Alwin to pull ahead by a stroke.

West, the defending champion who has won the tournament three times, took himself out of contention with a triple-bogie 7 on No. 13; he overshot the green on two straight chips.

Disaster struck Alwin on the 17th when he drove his five-wood tee shot into deep rough. His second shot carried only 25 feet. Then he hit within seven feet of the cup, but missed the putt and settled for a double-bogey 5.

Things got even worse on No. 18. Alwin reached the green on the par-4 400-yarder in regulation. His putt for a birdie from 18-foot rolled over the cup. Needing to sink a two-foot putt for par, Alwin tapped the ball across the lip of the cup and three inches past.

Marlowe, playing behind Alwin, placed his second shot on the fringe of the 18th green. He then left his putt 1 1/2 feet shy to set up the winning finish.

"I didn't know Alwin had bogeyed the 18th until I sank the last putt and everyone cheered," Marlowe claimed. "I thought I needed a birdie on No. 18 to force a playoff."

Ron Terry of Edgewood, who sank a 75-yarder for an eagle 2 on the 365-yard seventh-hole finished with the day's low score, 69, and in a second-place tie (211) with Alwin.