Columbia's Marty West, the two-time defending champion, scrambled to tie the 16th and 18th holes, then parred the first extra hole to turn back a semifinal challenge by Crofton's Bill Molloy in the 63rd Maryland Amateur Golf Championship yesterday at Prince Georges Country Club .

West will shoot for his seventh Maryland Amateur in today's 36-hole final against Regan O'Rourke of Bethesda.

O'Rourke recovered from a four-hole deficit by winning six holes on the back nine, then made a four-foot birdie putt on the 18th hole to edge Webb Heintzelman of Washingtonian, 1 up.

West had breezed through three matches, including a 5-and-3 morning quarterfinal victory over 1965 titlist Harry Cain of Bethesda.

But Molloy, 20, who shot a back nine of four-under-par 32 for 70, played extremely well.

"I had not heard of him at all," said West, 34. "This young man impressed me with his heart and his ability with a golf club. I hope I've got something left for tomorrow."

With the match even going to the 460-yard, par-4 16th hole, West drove into high weeds behind trees. He had to play his second shot sideways, back to the fairway, and was left with 195 yards to the green for his third shot. He used a four-iron and knocked the ball 15 feet from the hole and made the putt to match Molloy's par.

The match was still even going to the par-5 18th. West hooked into high weeds near a lake but played safely back to the fairway and wedged his third shot three feet from the cup. Molloy went for the green in two, missed to the right, but chipped up five feet from the hole and made birdie. West's three-footer sent it to extra holes.

Molloy pulled his tee shot behind trees on the par-4 playoff hole and ended up losing the match when his 10-foot par putt slid by the hole. West hit the green in two and two-putted for par.

O'Rourke, who played this season for AU, eagled No. 11 to pull within two holes, then caught up when Heintzelman twice three-putted.

"I think it's going to be a great final," O'Rourke said. "It doesn't matter where Marty hits it, he'll make par. He's got an unbelievable short game and great concentration."

In other morning quarterfinals, Molloy edged Mark Shuman of Germantown, 2 up; Heintzelman was five holes up with five to go and eventually closed out Henry Blue of Green Spring Valley, 3 and 1; and O'Rourke matched West's two under par in downing former Walker Cup player Doug Ballenger of Holly Hills, 5 and 3.