AUSTIN, Texas -- Hometown favorite Jordan Spieth and world No. 2 Rory McIlroy were among the highest ranked players to lose their first-round of pool play matches in the first wave of finishers on Wednesday at the World Golf Championships-Dell Technologies Match Play at Austin Country Club.
Spieth, the world's fifth-ranked player, fell to Japan's Hideto Tanihara 4 and 2 after conceding the match on the 16th hole. Spieth, who is from Dallas and was a member of the University of Texas' national championship men's golf team in 2012, never led in his match against the 54th-ranked Tanihara and was down three holes after a bogey on the par-5 12th.
Defending champion Jason Day of Australia withdrew from the tournament after six holes to be with his ailing mother, who has been diagnosed with terminal lung cancer and will have surgery on Friday in Columbus, Ohio.
Tanihara was at even-par for his round after 15 holes and was happy to sit back and let Spieth's uncharacteristic inconsistency get the best of him.
McIlroy, from Northern Ireland, was bested 2 and 1 by 62nd-ranked Soren Kjeldsen of Denmark. The match was square through 15 holes before Kjeldsen birdied the par-5 16th and nearly holed his tee shot on the short, par-3 17th, with his ball stopping three feet behind the pin.
Day, ranked No. 3 in the world, conceded his first-round match in pool play on the sixth green. He was 3-down to Pat Perez after a double bogey on the par-5 fifth. Perez had birdied both the par -4 second hole and the par-3 fifth.
Every golfer competes in at least three matches in this event as the field is divided into pool play, with 16 groups of four golfers. Each player in every group goes head-to-head once in rounds Wednesday, Thursday and Friday. A win is worth one point and a tie scores a half point. The golfer who amasses the most points from his three matches moves on to single elimination play on the weekend.
Other results from the opening wave on Wednesday included: No. 20 Brooks Koepka over No. 34 Kevin Kisner by a score of 6 and 5; No. 23 Louis Oosthuizen of South Africa over No. 47 Ross Fisher of England, 4 and 3; No. 30 Thomas Pieters of Belgium over No. 39 Scott Piercy, 3 and 2; No. 24 Charl Schwartzel of South Africa over No. 45 Byeong Hun An of South Korea, 6 and 5; and No. 12 Paul Casey of England over No. 60 Joost Luiten of the Netherlands 2 and 1.
Also winning Wednesday were: No. 33 Gary Woodland over No. 26 Emiliano Grillo of Argentina, 3 and 2; No. 48 William McGirt over No. 19 Brandt Snedeker 2 up; and No. 15 Branden Grace of South Africa over No. 52 Andy Sullivan of England, 4 and 2.
The only halved match in the early wave Wednesday was between No. 32 Ryan Moore and No. 37 Yuta Ikeda of Japan.
NOTES: There are 20 countries represented in the 64-player field, tying for the most ever, with the United States leading the way with 27 players in the field. England was represented by nine players, while South Korea had four. Japan, Spain and South Africa each have three players. ... The three highest-seeded players to win the Dell Technologies Match Play are Kevin Sutherland (No. 62 in 2002), Steve Stricker (No. 55 in 2001) and Geoff Ogilvy (No. 52 in 2006). ... Tiger Woods owns the record for the largest winning margin in the final (scheduled 36 holes) with his 8 and 7 win over Stewart Cink at The Gallery at Dove Mountain in 2008. Jason Day's 5 and 4 victory in last year's Championship Match was the largest margin since Woods defeated Cink.