AUSTIN, Texas (AP) The Latest on the Dell Technologies Match Play (all times local):
On a day when other top seeds didn't fare very well, Dustin Johnson made short work in his debut as the No. 1 seed.
Johnson made five birdies in his opening eight holes and never gave Webb Simpson much of a chance in a 5-and-3 victory at the Dell Technologies Match Play.
Of the top five seeds, Rory McIlroy (2) was beaten by four straight birdies from Soren Kjeldsen. Jason Day (3) withdrew to be with his mother as she has surgery Friday for lung cancer. Jordan Spieth (5) lost on the 16th hole to Hideto Tanihara, who was making his Match Play debut.
Hideki Matsuyama, the No. 4 seed, halved his match against Jim Furyk.
McIlroy and Spieth now need some help to advance out of their four-man group into the knockout stage on the weekend at Austin Country Club.
Jason Day says his mother, Dening, is having surgery Friday for lung cancer and he wants to be with her.
Day walked off the course when he was 3 down after six holes to Pat Perez. He made a brief appearance in the media center and could barely talk through his tears as he said was going home to Ohio.
Day says doctors in Australia said her cancer was terminal and that she had 12 months to live. He brought her to Ohio for more tests, and doctors are hopeful there is a chance for recovery.
Defending champion Jason Day has conceded his match to Pat Perez - after six holes.
Details were unclear why the Australian stopped after a double bogey to fall 3 down after six holes. Day tweaked his back in the Dell Technologies Match Play a year ago but still went on to win all seven of his matches.
Because of the round-robin format, Day is still in the tournament. But he has a tough road to win his group with the loss.
Add Jordan Spieth to the list of surprising first-round losses in the Dell Technologies Match Play.
Spieth, the No. 5 seed, fell behind on the seventh hole at Austin Country Club against Hideto Tanihara and never caught up. Spieth didn't win a hole until he was conceded a bogey on the 14th hole. Tanihara wound up winning, 4 and 2, in his Match Play debut.
It was the first time Spieth has lost in the opening match in four appearances.
Rory McIlroy, the No. 2 seed, was beaten earlier by Soren Kjeldsen of Denmark.
The shortest day so far belongs to former Masters champion Charl Schwartzel, a 6-and-5 winner over Byeong Hun An.
Rory McIlroy faces a tough road if he wants to advance out of his group in the Dell Technologies Match Play.
Soren Kjeldsen of Denmark birdied his last four holes to beat McIlroy in a wild opening match at Austin Country Club. They halved only five of the 17 holes they played. Kjeldsen finished off the No. 2 player in the world with a tee shot into 2 feet on the par-3 17th.
It was the first time since 2013 that McIlroy lost in the opening round. The good news? It's not single elimination like it was in 2013, and McIlroy still has two more matches to try to win his group.
Rory McIlroy was no different from the other 63 players at the Dell Technologies Match Play. He wasn't sure how long he would be staying.
Match Play began Wednesday at Austin Country Club with 32 matches a day for the opening three rounds of group play. McIlroy drove right into the tree and wound up losing the opening hole of his match against Soren Kjeldsen.
Jason Day is the defending champion, though McIlroy has been tough in this format. His record is 11-2-1 over the last two years, with one of those losses in a meaningless consolation match a year ago.
Dustin Johnson, the No. 1 seed, plays in the afternoon.
The top player from each of the 16 four-man groups advances to the weekend of single-elimination matches.