LOS ANGELES (AP) Australia's Travis Smyth knocked off No. 3-ranked Braden Thornberry in the morning and advanced to the U.S. Amateur quarterfinals in the afternoon with a 2-and-1 victory over No. 12 Will Zalatoris on Thursday.
Smyth is on an impressive run at Riviera Country Club with a chance to follow the path set by Curtis Luck. Smyth's good friend and fellow long-haired Australian won the Amateur last year at Oakland Hills.
Smyth excelled in a 3-and-2 victory over NCAA champion Thornberry, who beat world No. 1 Joaquin Niemann on Wednesday. Smyth finished off Zalatoris with a birdie on the 17th aided by a remarkable chip from the bunker.
Smyth is a former rugby player who only picked up golf at 12 years old while recovering from an injury.
He handled the grind of a two-round day with steady effort and an afternoon mental reset on the 13th, where he saved par after his 4-up lead had dwindled to 2-up.
''This format, it's very tough,'' Smyth said. ''You want to get yourself into match play and then just play as best you can. ... I just concentrate on my next shot. The more I think about how good these guys are - and they're all good - I think that's taking me away from what I need to do.''
Chicago-area player Doug Ghim also advanced to the quarterfinals while wearing a Cubs cap, beating Californians in back-to-back matches. Ghim, the Big 12 Player of the Year at the University of Texas, followed up a 19-hole victory over Pepperdine junior Sahith Theegala with a 3-and-2 win over El Cajon's Joey Vrzich in the afternoon.
After the world's top two ranked players lost on Wednesday, several more big names fell on the draining Thursday. Only two of the top eight seeds are among the final eight players left in the championship.
Medalist Hayden Wood also lost in the Round of 32, falling 4 and 3 to Norway's Kristoffer Ventura - his teammate at Oklahoma State.
But Scotland's Connor Syme eliminated Ventura in dramatic fashion in the afternoon, holing a 75-foot chip from the fringe on the 18th hole to win 1 up.
''That's just the coolest way to finish out a match,'' Syme said. ''It was awesome.''
Ventura had repeatedly rallied to catch up during their tense round, but Syme continued his strong run after knocking off No. 2-ranked Maverick McNealy on Wednesday in the Round of 64.
''I'm just really enjoying myself this week,'' Syme said. ''It's a special place, Riviera. It's an absolutely awesome golf course.''
Fourth-seeded Theo Humphrey is the highest-rated remaining competitor after wins over Kyle Mueller and Noah Norton. Humphrey, a Vanderbilt player from Connecticut, is adjusting solidly to the challenges of unfamiliar West Coast grass.
''The rough is what's completely different,'' Humphrey said. ''I've never seen anything like it before. It's weird. It looks like it's always sitting up and it's going to be easy. Somehow it finds a way to be pretty challenging.''
No Californians are left in the field after four afternoon defeats. Taiwan's Chun An Yu beat Los Angeles-area player Collin Morikawa 2 up, and USC freshman-to-be Cheng Jin of China lost 2 and 1 to Dawson Armstrong.
Play continues through Sunday at Riviera.