Collegians Swing Into Amateur Golf Lead : Golf: Jun, Demsey share lead with La Jolla’s Merhar going into today’s final round.

The event is the San Diego Men’s Amateur Golf Championship. But looking at the leader board at Balboa Golf Course after the third round, you had to wonder if it wasn’t the San Diego junior championship.

The tournament that has been dominated by baby boomers in recent years is being threatened by two baby-faced kids.

Mike Jun, whose only facial hair is peach fuzz, and Todd Demsey, who has a mild case of acne, are tied for the lead heading into today’s final round at Torrey Pines South. Both are 19-year-old college players.

Both have shot 212 through three rounds to share a one-stroke lead over former pro Frank Merhar, 49, of La Jolla. Ed Cuff, the 1981 champion, was two back at 144 playing in a foursome with Jun, Demsey and Merhar.

Jun, who just finished his sophomore season at San Diego State and plans to redshirt next year, shot one-under-par 71 on the 6,058-yard course Saturday. Demsey, who was a redshirt his freshman year at Arizona State, was one of five players in the top six to card a 70.

Four-time defending champion Pat Duncan, 35, also shot a 70. But sitting in a fourth-place tie with Ed Curtis at 218, Duncan was left contemplating where he was at 19.

“When I was 19 . . . I think I was in junior college,” he said. “But what’s that? Twenty, 21?”

It took Duncan, the amateur champ five of the past six years, a while to reveal that, at 19, he had grown his blond hair down to the middle of his back and quit golf for throwing Frisbees on the beach. That, after he earned All-San Diego Section honors along with PGA mainstay Scott Simpson as a junior at San Dieguito High.

To win another championship today, Duncan would need to make up seven strokes.

“If there’s any course you can do it on it’s Torrey South,” said Duncan, a Rancho Santa Fe landscaper. “If you shoot a 68 or 67, you got a good chance. If he shoots a respectable 74, you got him. The problem is I gotta catch two guys.”

The two teen-agers, in fact, showed no signs of faltering.

Jun birdied three holes on the front nine and was pleased with his drives, considering everything he’s hit in practice the past few weeks has hooked. Demsey birdied three holes on the back nine after an erratic front side, on which he eagled No. 7 then double-bogeyed No. 9. Demsey credited his putting and the fact that he was steady playing his first tournament since August.

“I would have liked to have taken charge today,” said Demsey, who finished seventh last year as a Torrey Pines High senior. “But after that double bogey on nine, I feel fortunate to have brought it back. I putted pretty good for me. I didn’t miss any short ones.”

Jun said he was surprised to be leading and he’s lucky to be playing. He and his former Madison High and current SDSU teammate, Kevin Riley, missed the registration deadline and were entered in place of two first-round no-shows. Had Riley not given Jun a 5 a.m. wake-up call the previous Saturday, Jun would have slept through the tournament. He was on the phone until four that morning, talking to his girlfriend.

With one hour’s sleep, he shot a 73. He emerged Sunday with a four-under 68 to take a one-shot lead into the third round. All things considered, though, Jun still isn’t satisfied.

“I’m surprised (to be leading),” he said. “Before the tournament I was hooking everything left. I was hitting the ball straight today, but I was putting really bad.”

Jun was too short on a 30-foot first putt as he bogeyed four. He went long on a 25-footer and bogeyed 13. On 14, he had a three-footer for a birdie and rimmed it right.

Demsey said he felt left out in the cold as ASU, which now is playing in the NCAA tournament, won the West Region tourney two weeks ago. Demsey believes he is one of the top five players on a Sun Devil team that features two-time defending NCAA medalist Phil Mickelson from San Diego.

Before he got careless on the ninth hole, Demsey proved his point on the par-five, 470-yard seventh hole. He crushed a 260-yard drive on the slight dog-leg right, left his second shot on the fringe then hit a perfect wedge that trickled in from 70 yards for the eagle.

“I knew it had a chance; I’ve been chipping good,” said Demsey, who, like Jun, shot a second-round 68 after a first-round 74 at Torrey Pines. “I’d like to be playing at the NCAA’s now, but I’m real excited to be playing this tournament. I haven’t played in a tournament for so long.”

After a 73 and a 75 in the first two rounds, Duncan posted a more familiar 70 Saturday. But when he was able to pick up only one stroke on the tournament’s fresh-faced leaders. Maybe it was time for Duncan to consider a nostalgic trip to the beach.

“Wait a minute,” he said. “Nineteen? That’s 16 years ago, bud.”