Demsey Vaults Into the Lead With Deft 66 : Golf: Arizona State player holds a two-shot edge in SCGA Amateur Championship. Canoga Park’s Baker slips to seventh.

Todd Demsey literally dropped a stroke on the field in the early stages of the Southern California Golf Assn. Amateur Championship.

Just gave away a shot, simple as you please. It was embarrassing.

While playing his second hole, Demsey clumsily dropped his putter, which landed on his ball and moved it slightly. A five-foot putt for birdie was then transformed into a bogey after an ensuing penalty stroke and two more strokes to hole out.

“My caddie didn’t wipe my grip,” Demsey quipped.

One day, Demsey dropped strokes and the next he picked them up in bunches. As a result, he might soon be gripping the championship trophy.

The Arizona State standout from Rancho Santa Fe fired a sizzling six-under-par 66 at Brentwood Country Club on Saturday and took a two-shot lead with 18 holes to play.

Demsey, 21, bogeyed the first hole, then reeled off three birdies in a row. Before the day was complete, he had stormed past 36-hole leader Mark Johnson of Barstow, who shot 73 and trails Demsey by two.

Demsey, the defending NCAA Division I champion, was two shots off the course record, which is shared by Jerry Barber, among others. Head-turning scores by Demsey, built like a graphite shaft at 6-foot-2 and 160 pounds, are nothing new. In the fall of 1991, Dempsey shot an 11-under 61 on a 7,600-yard course in Carefree, Ariz.

In terms of players from the region, Demsey’s sparkling 66 meant they were essentially 86’d. The final round will begin today at 7:30 a.m.

Don Baker of Canoga Park, a former PGA Tour professional who regained his amateur status, failed to make a move on the leaders. Baker, 41, started the round tied for third place and two shots behind Johnson.

Baker, however, shot 75 and fell into a five-way tie for seventh at 219, seven shots behind Demsey. His play on the four par-five holes, which he toured at one over, was his downfall.

“That’s about three strokes higher than it should be,” Baker said.

Particularly unnerving was a 50-yard pitch shot that Baker faced on the par-five eighth. He was one over at the time and coming off a birdie but dumped a wedge shot into a greenside bunker and made bogey.

“That was ugly, no doubt about it,” he said. “I just misjudged it.”

Tony Bordwell, who plays at Cal State Northridge, had the low round among players from the region. Bordwell, who shot 70, was one of six players in the 45-man field to break par under ideal conditions. Bordwell was one of four players tied at 221.

“I played real well,” said Bordwell, who had five birdies. “I didn’t make many mistakes at all.”

Even when he did, things turned out fine--if not better. On the eighth hole, Bordwell nearly reached the green in two, but his second shot buried under the lip of a sand trap.

Since he couldn’t move the ball toward the flagstick, Bordwell hit a shot laterally into the back of the bunker, then blasted into the cup for a birdie.

Mike Turner of Woodland Hills, playing in Bordwell’s threesome, shot 74 and is at 225.

Charlie Wi of Thousand Oaks and two-time defending champion Craig Steinberg of Van Nuys failed to mount a charge. Each shot 74, fell back to 226 and fought a losing battle to find their putting strokes.

Wi three-putted four times, while Steinberg had 34 putts.