Play is officially underway at the WGC-Dell 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: (1) Jordan Spieth def. (51) Jamie Donaldson, 3 and 2: The top seed cruised rather easily, winning five of the first seven holes against the former Ryder Cup hero. Spieth held a 3-up lead at the turn and barely received a challenge from Donaldson on the inward half.
Group 1: (39) Victor Dubuisson def. (31) Justin Thomas, 3 and 2: Dubuisson was a runner-up at this event two years ago, and he dispatched of Thomas on a day when the American struggled to score. Dubuisson won seven holes during the match, but three of those holes were won with par while a bogey on No. 14 was good enough to take a 3-up lead.
Group 2: (2) Jason Day def. (62) Graeme McDowell, 3 and 2: McDowell got off to an early lead before Day came roaring back, winning four holes from Nos. 8-12. The match took on the feel of a Pyrrhic victory, though, as Day appeared to injure his back late in the round and was barely able to stand by the match's final hole.
Group 2: (36) Thongchai Jaidee def. (26) Paul Casey, 2 and 1: Jaidee scored the day's first upset, defeating Casey who made a run to the quarterfinals at this event last year. Casey won the fifth hole to take an early lead, but Jaidee won the very next hole and never trailed the rest of the way, seizing control with three wins in five holes from Nos. 10-14.
Group 3: (3) Rory McIlroy def. (64) Thorbjorn Olesen, 1 up: The defending champ escaped - barely. McIlroy put forth a sloppy effort and was 2-down with five holes to play, but he turned things around in the nick of time. Wins on Nos. 14 and 15 squared the match, and a par on the home hole was good enough to edge the Dane.
Group 3: (26) Kevin Na def. (46) Smylie Kaufman, 2 and 1: Kaufman held a 1-up lead through 11 holes, but he played the subsequent four holes in 2 over. That allowed Na to turn a slim deficit into a 3-up advantage, and the veteran held on from there for the win.
Group 4: (33) Emiliano Grillo def. (21) J.B. Holmes, 3 and 2: Grillo took care of business quickly, winning five of the match's first seven holes. While Holmes battled back, he never got closer than 3-down during the back nine as the Argentine cruised to a full point.
Group 4: (4) Bubba Watson vs. (63) Patton Kizzire, halved: This was a close contest, as neither player held more than a 1-up lead at any point in the match. Watson appeared to take control when Kizzire bogeyed the par-3 17th, but the rookie turned around and birdied the final hole to scratch out a tie.
Group 5: (58) Jason Dufner def. (5) Rickie Fowler, 2 and 1: Fowler was a popular pick to win this week, but he faces an early deficit after Dufner blew past him in the opening match. Dufner held a 3-up lead through 11 holes, but Fowler won three of the next four holes to square the match. Dufner regained the lead with a birdie on No. 16, then closed out Fowler on the next hole.
Group 5: (27) Byeong-Hun An vs. (47) Scott Piercy, halved: Unlike last year, pool-play matches that are tied after regulation do not go to extra holes. That means An and Piercy both start the week with a half-point, as An held a 3-up lead through 13 but watched as Piercy won three of the final five holes for the draw.
Group 6: (30) Bill Haas def. (41) Chris Wood, 2 and 1: Wood got off to a quick start and held a 2-up lead through eight holes, but Haas battled back and took a lead for the first time in the match on No. 13. Wood failed to win a single hole on the back nine, allowing Haas to draw first blood.
Group 6: (6) Adam Scott vs. (55) Thomas Pieters, halved: Scott appeared to be in control of this match down the stretch, holding a 2-up lead for much of the back nine. But Pieters won Nos. 16 and 17 to square the match, then rolled in a 5-foot par putt on No. 18 to steal a tie from the Aussie.
Group 7: (28) Matt Kuchar def. (48) Anirban Lahiri, 6 and 5: The biggest margin of victory on the opening day belonged to Kuchar, who dominated from the start. He won four of the first eight holes and went eagle-birdie on Nos. 12 and 13 to close out Lahiri, who didn't win a single hole.
Group 7: (7) Justin Rose def. (57) Fabian Gomez, 2 up: Rose made the turn with a 2-up lead and appeared to be on cruise control when he extended the advantage to 4-up through 12. But Gomez won three of the next four holes to give himself a glimmer of hope before running into trouble on No. 18.
Group 8: (49) Robert Streb def. (8) Dustin Johnson, 3 and 2: Johnson didn't win a hole until No. 10, allowing Streb to build a 3-up lead at the turn. Johnson made up a little ground on the back nine, but he never got closer than 2-down allowing Streb to record a relatively stress-free upset win.
Group 8: (37) Kiradech Aphibarnrat def. (22) Jimmy Walker, 2 and 1: Walker has plenty of experience with Texas golf and built an early lead, but Aphibarnrat battled back and notched an impressive win. The Thai won five holes in a six-hole stretch from Nos. 7-12 and Walker suffered an ill-timed double bogey on No. 16.
Group 9: (17) Phil Mickelson def. (42) Matthew Fitzpatrick, 5 and 4: One of the few early blowouts went the way of Mickelson, as the veteran schooled the youngest player in this week's field. Mickelson took control with four straight wins on Nos. 6-9, and Fitzpatrick never even won a single hole during the match.
Group 9: (9) Patrick Reed def. (53) Daniel Berger, 1 up: Reed never trailed after a hot start that included wins on four of the first five holes, but Berger battled back to make things interesting. Berger was 2-down with two holes to go, but extended the match with a birdie on No. 17 before Reed closed him out with a birdie on the final hole.
Group 10: (18) Brooks Koepka def. (40) Billy Horschel, 3 and 2: Horschel got off to a hot start and led 3-up after just six holes, but Koepka launched an impressive rally. A win on No. 7 was followed by four straight on Nos. 9-12, as Koepka won seven of the match's final 10 holes.
Group 10: (10) Danny Willett vs. Jaco Van Zyl, halved: This was another closely-contested match, as each player won three holes while the remaining 12 were halved. Van Zyl led at the turn, but it was Willett who led through 15 holes. Van Zyl squared the match on No. 16, and the final two holes were halved.
Group 11: (54) Chris Kirk def. (11) Branden Grace, 3 and 1: Grace starred at the Presidents Cup in Korea, but he ran into a buzzsaw in Kirk in his opening match. The American won each of the first three holes and played his first six holes in 5 under, buildling a 3-up advantage at the turn. From there, Grace only won a single hole.
Group 11: (32) Russell Knox vs. (38) David Lingmerth, halved: Knox and Lingmerth are friends and live near each other in Northeast Florida, and they played to a draw on Wednesday. Neither player held more than a 1-up lead at any time, and Knox's birdie on the par-3 17th drew him even and ultimately earned him a half-point.
Group 12: (20) Kevin Kisner def. (43) Soren Kjeldsen, 2 and 1: Kisner won the first two holes of the match and never looked back. The American built a 3-up lead through five holes, and appeared in total control with a 4-up advantage through 13 holes. While Kjeldsen battled back to cut his deficit in half, Kisner eventually closed him out for a decisive win.
Group 12: (52) Rafael Cabrera-Bello def. (12) Hideki Matsuyama, 1 up: Cabrera-Bello won two of the first four holes and never trailed against Matsuyama, taking a decisive lead with a birdie on No. 17. It's a big win for the Spaniard, who is one of seven players in the field not yet qualified for the Masters but would make the field should he advance to the quarterfinals.
Group 13: (13) Sergio Garcia def. (59) Lee Westwood, 1 up: This was a back-and-forth contest, as Garcia held a 2-up lead through three holes before Westwood won four in a row. Garcia then won four straight holes on Nos. 9-12 and never trailed again, ultimately closing out Westwood with an eventful par on No. 18.
Group 13: (25) Marc Leishman vs. (45) Ryan Moore, halved: Leishman never trailed in the match and appeared on his way to victory, but he only left with a half-point. Moore won the 12th hole to trim his deficit to 1-down, then escaped with a draw after Leishman made a sloppy bogey on No. 18.
Group 14: (14) Zach Johnson def. (60) Marcus Fraser, 4 and 3: This was an easy win for the reigning Open champ, who birdied three of his first four holes to build an early advantage. Johnson held a 1-up lead at the turn and then took control with three wins in a four-hole stretch from Nos. 11-14.
Group 14: (44) Martin Kaymer def. (24) Shane Lowry, 1 up: Kaymer won a closely contested match that saw neither player hold more than a 1-up lead. Lowry held a lead on three separate occasions, but he conceded on No. 16 to level the match and then Kaymer took his final lead of the day with a par on No. 17.
Group 15: (15) Brandt Snedeker def. (56) Charley Hoffman, 2 and 1: Snedeker was the first player to get a point on the board, turning a close match into a victory with a decisive closing stretch. Hoffman actually held a 1-up lead through 13 holes, but Snedeker won each of the next three holes before closing out the match with a par on No. 17.
Group 15: (19) Charl Schwartzel def. (34) Danny Lee, 1 up: The South African is making his first start since winning in Tampa, and he continued that momentum by eking out a win against the Kiwi. Schwartzel never trailed, but he also never held more than a 2-up lead. Lee leveled the match with a par on No. 16, but Schwartzel birdied the next hole to take the lead for good.
Group 16: (16) Louis Oosthuizen def. (61) Matt Jones, 2 and 1: Jones held his own and actually led 1-up through 11 holes, but Oosthuizen emerged on the back nine. The South African rolled in three birdies in a five-hole stretch from Nos. 12-16, and closed out the match with a par on No. 17.
Group 16: (29) Andy Sullivan def. (35) Bernd Wiesberger, 3 and 2: Sullivan won three of the first five holes, led 4-up at the turn and never trailed in the match. While Wiesberger won three straight holes from Nos. 11-13, it was too little, too late.