Jordan Spieth, who had not trailed in any match until he bogeyed the fourth hole on Saturday morning, never recovered and lost to South African Louis Oosthuizen, 4 and 2, in the round of 16 in the WGC-Dell Match Play.
Oosthuizen, a former Masters champion who is ranked 18th in the world, won the 11th, 12th and 13th holes at Austin Country Club in Austin, Texas, to wrest control of the match from No. 1-ranked Spieth. Oosthuizen will play Dustin Johnson, a 3 and 2 winner over Patrick Reed, in the quarterfinals Saturday afternoon.
Jason Day, meanwhile, won the first hole of his match with Brandt Snedeker and never trailed in a 3 and 2 win. Day, seeking a second straight victory, faces Brooks Keopka, a 1 up winner over Matt Kuchar, in a quarterfinal match.
Rory McIlroy, the defending champion, was pushed to the final hole by Zach Johnson and had to match Johnson’s birdie there to win, 1 up. McIlroy will face Chris Kirk, a 2 and 1 winner over Bill Haas, in the quarters.
In the other quarterfinal match, Rafa Cabrera Bello, who defeated Byeong-Hun An when An withdrew, will face Ryan Moore, a 4 and 3 winner over Patton Kizzire.