Play is underway at the WGC-Dell Technologies Match Play, as 64 players take on Austin Country Club with hopes of advancing out of pool play. Follow along here to see how the first matches played out, and who is in line to advance to the Round of 16:
Group 1: Dustin Johnson (1) vs. Webb Simpson (58), 5 and 3: The top overall seed made quick work of the former U.S. Open champion, running off eight birdies in 15 holes and looking like the player to beat. After going one-and-done nearly every year in the old format, Johnson reached the quarterfinals last year despite an opening-day loss.
Group 1: Martin Kaymer (41) def. Jimmy Walker, 3 and 2: Kaymer turned a close match into a comfortable victory by making birdie on the 10th, 11th and 16th holes. A tough match lies ahead against the world No. 1.
Group 2: Soren Kjeldsen (62) def. Rory McIlroy (2), 2 and 1: In the day’s biggets upset, Kjeldsen birdied four consecutive holes late on the back nine to stun McIlroy, one of the pre-tournament favorites. McIlroy had a 1-up lead with five to play, but Kjeldsen, the 41-year-old from Denmark who doesn't have a top-25 in any of his seven starts this year, ran off four consecutive birdies to put the heat on McIlroy. He closed out the match with a tee shot to 3 feet on 17 – his fifth consecutive approach shot inside 10 feet.
Group 2: Gary Woodland (33) def. Emiliano Grillo (26), 3 and 2: Down two holes early to Grillo, who was coming off a good week at Bay Hill, Woodland went 6 under the rest of the way, including the usual match-play concessions. Woodland reached the finals of this event in 2015, during the first year of the round-robin format.
Group 3: Pat Perez (56) def. Jason Day (3), conceded: Perez seized an early 3-up lead through six holes before Day walked off the course. Day later withdrew from the event, after disclosing that his mother has lung cancer and will undergo surgery Friday.
Group 3: Marc Leishman (28) def. Lee Westwood (43), 3 and 2: Leishman, who won last week at Bay Hill, stayed hot at Austin Country Club, leading the entire way against Westwood, the most experienced WGC player of all time. Leishman held a narrow 1-up lead on 13 tee, but he birdied 13 and stuffed his approach on 15 to tap-in range to seal the match. With a full point upcoming because of Day's withdrawal, Leishman and Perez, his Thursday opponent, are in the best position to advance.
Group 4: Hideki Matsuyama (4) vs. Jim Furyk (51), halved: Matsuyama and Furyk halved the last eight holes of the match. Furyk missed several good birdie opportunities on the back nine, but it was Matsuyama who squandered a chance to earn the full point, after pitching to 8 feet on the final hole and then missing the putt.
Group 4: Louis Oosthuizen (23) def. Ross Fisher (47), 4 and 3: Oosthuizen, last year’s finalist, cruised to a stress-free victory over Fisher, keeping the pressure on throughout the match by making three birdies and zero bogeys.
Group 5: Hideto Tanihara (54) def. Jordan Spieth (5), 4 and 2: In another big upset on Day 1, Spieth never led against the 38-year-old Japanese star, who has 13 career titles overseas. Spieth beat himself, playing his last nine holes in 3 over and hitting only one green to end his chances. It’s the first time in four years that Spieth has lost his opening match.
Group 5: Ryan Moore (32) vs. Yuta Ikeda (37), halved: Moore was in good position to close out the match but airmailed his wedge shot into the final green. Ikeda earned a half point by making his 5-footer for birdie.
Group 6: Justin Thomas (6) def. Chris Wood (49), 2 and 1: Facing a one-hole deficit with five holes to play, Thomas won Nos. 14 and 15 to take the lead, then closed out the match with a par on 17.
Group 6: Kevin Na (46) def. Matt Fitzpatrick (27), 5 and 4: Na took a 5-up lead through eight holes and never let up, losing only one hole to the former U.S. Amateur champion. Na has proven a tough out in this format; last year he lost a sudden-death playoff to McIlroy that kept him out of the Round of 16.
Group 7: Sergio Garcia (7) vs. Shane Lowry (53), halved: Lowry took a 1-up lead to the last, but he drove left, into the hazard. Garcia had holed a clutch birdie putt on 16 to stay alive, then stole a half point when Lowry missed a 5-footer for par on 18.
Group 7: Jon Rahm (21) def. Kevin Chappell, 38, 3 and 2: Rahm, playing in his first Match Play, took advantage of his awesome power to pull away down the stretch. He birdied the par-5 12th to take the lead, hit a wedge stiff on 15 and then got up-and-down from a greenside bunker on 16 to close out the match.
Group 8: Alex Noren (8) vs. Thongchai Jaidee (57), 3 and 2. Noren, a four-time winner last year on the European Tour, won the first two holes and never looked back, using an eagle on the 12th hole to eliminate any back-nine suspense.
Group 8: Bernd Wiesberger (36) def. Francesco Molinari (25), 2 up: Wiesberger led after the eighth hole, then put the exclamation point on the match with a 30-footer for birdie on the final green.
Group 9: Patrick Reed (9) vs. Jason Dufner (59), halved: Reed was 2 up with four to play, but Dufner rallied with a par on 15 and a 15-foot birdie on 17. The last hole wasn’t pretty, with Dufner finding a faiway bunker and Reed driving into the hazard. But both players made clutch par saves to earn a half point.
Group 9: Brooks Koepka (20) def. Kevin Kisner (34), 6 and 5: Koepka has struggled this season, with four missed cuts in six starts, but he had no problem dispatching Kisner, who last week shared the 54-hole lead at Bay Hill. Koepka made five birdies in the first seven holes and lost just one hole en route to the blowout win.
Group 10: Tyrrell Hatton (10) def. Charles Howell III (61), 2 and 1: The Englishman took advantage of consecutive bogeys by Howell on Nos. 13 and 14 to take control of a back-and-forth match. Hatton has been one of the most consistent players this year, finishing in the top 10 in his last four worldwide starts.
Group 10: Rafa Cabrera Bello (22) def. Jeunghun Wang (40), 3 and 2: Bello, who finished third in this event last year, had little trouble with his opening opponent, taking a 3-up lead through five holes. Bello’s pars on Nos. 14 and 15 gave him a comfortable cushion.
Group 11: K.T. Kim (64) def. Danny Willett (11), 4 and 2: Kim birdied the first two holes and never gave the reigning Masters champion a chance. Pars on 15 and 16 helped build the big margin of victory.
Group 11: Russell Knox (17) def. Bill Haas (42), 3 and 2: Knox never trailed in the match despite playing the first 15 holes in 1 under par.
Group 12: Charl Schwartzel (24) def. Ben An (45), 6 and 5: And to think, this match was all square on the sixth tee. Schwartzel won three of the next four holes – all with par – to build a big lead, then poured it on with back-to-back wins on Nos. 12 and 13 to close out the match and head to an early lunch.
Group 12: Paul Casey (12) def. Joost Luiten (60), 2 and 1: Casey, who has a strong record in this event, won the 15th with a conceded par and a birdie on the par-5 16th to put away Luiten, who had clawed back from an early 2-down deficit. Casey improved to 20-12-1 in this event.
Group 13: Bubba Watson (13) def. Jhonattan Vegas (55), 1 up: The left-hander hasn’t had much to smile about this year, but he did just enough to hold off Vegas despite the narrow lead throughout much of the match. The turning point came on 13, when Watson laid up and wedged to 11 feet for the decisive birdie.
Group 13: Thomas Pieters (30) def. Scott Piercy (39), 3 and 2: Still riding high from his breakout Ryder Cup performance, the big-hitting Belgian never trailed and coasted to the easy victory despite failing to make a putt longer than 4 feet.
Group 14: Phil Mickelson (14) def. Si Woo Kim (63), 5 and 3: Sharper than in his last appearance in Mexico, when he struggled off the tee, Mickelson made two birdies and a bogey on his front nine to build a 4-up advantage. Lefty never led by fewer than three holes on his way to an easy Day 1.
Group 14: Daniel Berger (35) def. J.B. Holmes (31), 7 and 5: Berger made six birdies and an eagle en route to a blowout victory over the big-hitting Holmes. Berger withdrew from this event a year ago, after injuring his wrist in a match against Mickelson. They’ll square off again Thursday.
Group 15: Branden Grace (15) def. Andy Sullivan (52), 4 and 2: Grace, who went 5-0 two years ago at the Presidents Cup, stayed hot in the match-play format, jumping all over the Englishman. Grace took a 1-up lead at the turn, but poured it on with birdies on Nos. 11 and 14 and concessions on both of the back-nine par 5s.
Group 15: William McGirt (48) def. Brandt Snedeker (19), 2 up: Thrown for a loop when his longtime putter broke about five minutes before his tee time, Snedeker coughed up a 1-up lead with four holes to play. McGirt, playing his first match-play event since 2007, went 2 under during that stretch, including a conceded birdie on 18.
Group 16: Matt Kuchar (16) vs. Brendan Steele (50), halved: Steele birdied 16 and 17 to take a 1-up lead into the final hole, but he hit his tee shot into the hazard and made bogey. Kuchar’s closing par was enough to give each player a half point.
Group 16: Tommy Fleetwood (29) def. Zach Johnson (44), 1 up: A tight match throughout, Fleetwood and Johnson halved nine consecutive holes before the Englishman stuffed his final approach to 2 feet for a conceded birdie and Johnson missed his 8-footer to halve the match.