Superstars Cameron Smith and Minjee Lee have fallen short in sudden-death playoffs on an epic and triumphant day for Australian golf in the US.
Resurgent former world No.1 Jason Day snapped a five-year, two-month PGA Tour title drought with a stirring victory at the $US9.5 million ($A14.3m) AT&T Byron Nelson Championship in Dallas, Texas.
Reigning major champions Smith and Lee were then poised to complete a glorious Aussie treble before being denied in sudden-death playoffs.
Smith produced a stunning birdie blitz at LIV Golf Tulsa to join American Dustin Johnson and South African Branden Grace in a three-man playoff with a record-setting nine-under-par 61 at rain-soaked Cedar Ridge.
But the British Open champ missed as 12-foot putt trying to match Johnson on the first extra hole.
Lee's near-miss was even more deflating.
The world No.6 looked on track to successfully defend her title at the LPGA Tour's Cognizant Founders Cup in New Jersey after opening up a two-shot lead with three holes to play.
Lee had let a three-stroke overnight lead slip after finding the water and posting a dreaded double-bogey five on the par-5 sixth.
But she tenaciously clawed her way back with a birdie at the very next hole before adding three more on the back nine to charge two shots in front standing on the 16th tee.
Alas, a three-putt on the 17th opened the door for former world No.1 Jin Young Ko, who marched through with a long bomb for birdie at the last before the Korean's par at the first extra hole proved good enough for victory.
"I heard the roar when Jin Young birdied 18, so I knew I was probably going to be tied if I didn't birdie the last hole," Lee said.
"I chipped it really well and it just missed, but I still think I played really solid today and throughout the whole week."
Starting the final round four strokes off the pace, Ko closed with a Sunday-best 67 to join Lee (71) at 13 under and force the playoff.
In a showdown of multiple major champions, Ko held firm as Lee faltered to leave the world No.3 to add the title and $US450,000 ($A677,000) winner's cheque to her 2019 and 2021 Founders Cup trophy collection.
Playing the par-4 18th again, Lee had a 20-foot putt from the fringe to defend the trophy she won last year, only to put it six feet past and then miss the return for a shock bogey.
Three weeks after claiming her maiden LPGA Tour win at the LOTTE Championship in Hawaii, Australian rookie Grace Kim closed with a 72 to finish tied for 10th at four under.
Sarah Kemp (72) was a shot further back in a share of 13th, with Karis Davidson (72) and Steph Kyriacou (77) finishing joint 31st.
With Reuters.
