Every year, the State Amateur golf tournament seems to produce its share of unknowns and upstarts. The 1989 tournament at Riverside Country Club is right onpar with history.

Sharm Newbold, who sneaked in as the 32nd seed a day earlier, and Greg Slack, a youngster who took up golf just three years ago, are this year's giant-killers who find themselves in the quarterfinals of Utah's premier amateur golf event after surviving the scorching heat Friday.Newbold, who less than 24 hours before was battling extra holes to grab the final spot in match play, knocked off medalist Ron Hitchcock 4 and 3 in the morning round, then came back to blitz Spence Ahrend 7 and 6 in the afternoon with an incredible 29 on the front nine.

Then there's Slack, a 16-year-old from Cedar City who is living in Farmington this summer. In his first-ever State Am, he defeated Mike Borich, considered by many to be the top amateur in the state, in 19 holes, then came back to knock off BYU golfer Roberto Herrera 2 and 1 in the afternoon.

Of course, there are some recognizable names left in the Final Eight. The top two are Eric Hogg, the 1981 State Am champ, and Brad Hansen, the 1986 champion. But only one of them has a chance to make it to the finals, since they meet in a quaterfinal match at 8:10 a.m.

Other quarterfinalists include BYU golfers Eddie Heinen and Ryan Rhees, and Rafael Ponce, who just used up his BYU eligibility, and Steve Brinton, a 38-year-old life insurance salesman.

After the morning's matchups which are Newbold-Ponce, Hogg-Hansen, Heinen-Rhees and Slack-Brinton, the semifinals will be played this afternoon. The two who survive today will come back Sunday morning to play a 36-hole final.

Newbold, a 21-year-old from Holladay, is trying to follow in his father's footsteps. Nineteen years ago, his father, Verl, arrived at Riverside as an unknown and proceeded to upset three players, including BYU All-American Chip Garris before losing in the semifinals. Friday, Verl was there every step of the way to watch his son's heroics as his caddy.

In the morning match Newbold played "all right" in knocking off Hitchcock, who may have been drained, physically and mentally, from his four-hole playoff for medalist honors the previous day. Then came his round of a lifetime in the afternoon against a shell-shocked Ahrend.

Newbold, who had made just two birdies total in the first two rounds, birdied the first three holes with putts from 10, 8 and 2 feet. After making a rare par at No. 4, he came back with a tap-in bird at No. 5, a 25-footer at No. 6 and a 4-footer at No. 7. He lost the 8th hole when he missed a 10-footer and Ahrend birdied, but came back with a 2-footer at No. 9 for a birdie.

Riverside pro Robert McArthur heard about Newbold's nine and excitedly told someone how he had a good shot at breaking Jay Don Blake's course record of 62. The only problem was, the match obviously was not going the full distance and it ended after three more holes, all pars for Newbold. After the match Ahrend told Newbold he ought to keep playing, since he was so hot.

"I was just hitting them close and making the putts," said Newbold with a shrug. `That was a career round and it just popped up from nowhere."

"I shoot 1-under and lose 7 and 6," said Ahrend, shaking his head.

Slack had plenty of folks shaking their heads with his play Friday. He took up golf at the age of 13 1/2 and has worked hard on his game the past couple of years. This summer he moved north to have a chance to play in more tournaments.

No one expected him to get past Borich, who had already won a half dozen tournaments this year, but he did on the first hole of a sudden-death playoff. Then against Herrera, the top remaining seed in the tournament, he found himself 1-down with six holes to play.

At the par-5 13th, Herrera outdrove Slack by a good 60 yards, but put his second shot behind a tree next to the green. Slack chipped up to within a foot and when Herrera couldn't sink his 20-foot birdie putt, he conceded the hole to make it even.

At the short par-4 14th, Herrera again appeared to have the advantage as he drove just short of the green and chipped to within three feet. Slack, meanwhile, had driven into the trees on the right and made a remarkable shot onto the fringe 30 feet away. He then rolled the ball into the center of the cup _ the ball actually popped up before falling back in _ and a shaken Hererra slid his short putt past the hole.

`That was the turning point," said Slack. "I putted well today and that kept me going."

At the next hole, Slack turned a disadvantage to his advantage by winning with a birdie after hitting his drive behind some trees on the left side. A 5-iron from 190 yards put him 10 feet away and he made the birdie putt.

Slack played much of the round with a "Raylor" wood, a 16-degree loft club that is between a 4- and 5-wood. The youngest player left will play the oldest player in Brinton, who made the quarterfinals for the first time in nearly two decades.

Brinton, who lost in the quarterfinals to Greg Sharp in 1971 before giving up competitive golf for nearly 15 years, is trying to uphold the honor of the older golfers.

"I'm the only senior citizen left," he said with a smile. "I've had a lot of guys come up to me and say `you've got to do it for us older golfers.' This certainly is an event for college and high school golfers."

Brinton defeated Weber State's Tom Concon in the second round 1-up after stopping Kenny Thomson in the first round 1-up.

Saturday's heavyweight match features former champions Hogg and Hansen. Hogg, who qualified for the U.S. Open last month, beat Dave Johnson 3 and 1 and knocked off 1988 semifinalist Joseph Summerhays 5 and 4. Hansen, who works in Carmel, Calif., as a stockbroker, edged 1984 champion Mark Davis 2 and 1 in the morning before beating John Taylor 6 and 4 in the afternoon.

Heinen and Rhees have played together many times on the Riverside layout as BYU teammates but now they'll go head to head in a suvival match. Heinen, a 19-year-old from Las Vegas, beat John Van Vleet and Kurt Bosen, while Rhees, a 22-year-old from Orem, played a lot of holes in beating Rich Rawdin 1-up and 17-year-old David Summerhays in 21 holes in the afternoon.

Ponce, a semifinalist last year, beat a pair of former runnerups in Jerry Rose and Doug Bybee.