Marty West of Columbia Country Club pulled even by winning the first three holes of the afternoon round, overcoming Regan O'Rourke's five-under-par golf in the morning round at Prince Georges, and went on today to win his seventh Maryland State Golf Association amateur championship, 3 and 2, at Prince Georges.

West, 34, a mortgage banker from Rockville, has won 15 straight matches in this tournament since losing to Gary Marlowe in the semifinals in 1980. In winning his third straight title, he inched closer to Ralph Bogart's record of 10.

"I'm just glad to say I finished three days of 36-hole matches," West said. "This is an endurance contest."

O'Rourke, 23, a former varsity golf star at American University, had West in trouble after the morning 18 when he birdied six of the final 13 holes. But after lunch, West made a 30-foot putt for birdie on the first hole, a 20-footer for birdie at No. 2 and won the third with a par.

"I felt like if I could put pressure on him; he hadn't had any pressure on him . . . " West said. "When I made those putts at one and two, he had the pressure right on top of him."

By the end of the front nine, West was 2 up, after shooting a 34 to O'Rourke's 40. West improved to 3 up when O'Rourke hooked his tee shot into trees and double bogeyed the par-5 11th hole.

West, twice named to the U.S. Walker Cup team, went 4 up with par on the 13th hole after O'Rourke missed a six-foot putt for par.

West's only mistake in the afternoon round came at the 15th hole, where he hooked his drive into a lake and allowed O'Rourke to pull to 3 down. But West closed out the match on the next hole, matching O'Rourke's par.

How good a pro golfer could West have been? "I think I could have made the tour," he said. "I could have made some money. Most people feel that they have to give it a try and make the big buck. It's a job for the guys on tour. Golf to me is for enjoyment. I have no regrets."

O'Rourke's morning round will not count as officially breaking PGA Tour player Joe Inman's course record of 70 set last year because West conceded a 20-foot birdie putt at the sixth hole.