LEMONT, Ill. (AP) _ Joel Kribel of Pleasanton, Calif., survived an extra-hole match in the morning, then crushed his opponent Thursday afternoon to advance to the quarterfinals of the U.S. Amateur.

Kribel parred the first playoff hole in his second-round match against Ian Kennedy of Baton Rouge, La., to win his second-round match on Cog Hill Golf and Country Club's Dubsdread course.

After lunch, he handed Edward Loar of Rockwall, Texas, a 7 and 6 defeat, playing Dubsdread's front nine in even par while Loar was posting a 6 and five 5s.

Kribel, a junior at Stanford who won the 1996 Western Amateur, advanced to the semifinals of last year's U.S. Amateur. He lost there to schoolmate Tiger Woods, who went on to win his record third straight title. Kribel will play Jason Bugg of Henderson, Ky., in Friday's first quarterfinal.

``Edward got into the position where he saw I was playing conservatively,'' Kribel said. ``He started firing at some pins, and it just added up to a few more bogeys.''

Bugg defeated Terry O'Loughlin of White Bear Lake, Minn., 2 and 1 in his third-round match, winning three of the last five holes.

Brad Elder of Overland Park, Kan., defeated 18-year-old Boyd Summerhays of Farmington, Utah, 2 and 1 in a third-round match during which both players were warned for slow play.

Elder, a senior at Texas who was second in this year's NCAA Championship, will play Michael Boyd of Tulsa, Okla. in the quarterfinals. Boyd knocked out Charles Warren of Columbia, S.C., who beat Elder in a playoff for the NCAA title, 5 and 4.

Randy Leen of Dayton, Ohio, the two-time Big Ten player of the year at Indiana, will face Ryuji Imada of Tampa, Fla., in the quarterfinals.

Leen beat Aaron Overholser of San Jose, Calif., 3 and 1 to advance, while Imada defeated Robert Floyd of Miami Beach, Fla., by the identical score. That knocked the most famous father-caddie on the grounds, Raymond Floyd, out of the championship and back to the Senior PGA Tour.

U.S. Junior Amateur champion Jason Allred of Ashland, Ore., lost his third-round match on the final hole by pulling a 2-foot putt. It lipped out, enabling Robert Gerwin of Cincinnati, to win the hole with a bogey and post a 1-up victory.

``I guess I kind of took it for granted,'' Allred said of his short putt. ``I'd putted well all week. It was a mental error, I guess.''

Gerwin will meet Matthew Kuchar of Lake Mary, Fla., in the last quarterfinal. Kucher scored a 1-up win over John Rollins of Richmond, Va.

The semifinals are Saturday and the 36-hole final is Sunday.