World number one Dustin Johnson overcame spirited resistance from Spain's Jon Rahm to make history by winning the WGC-Dell Technologies Match Play, his third tournament victory in succession.
Johnson became the first player to have won all four World Golf Championship events by beating Rahm by one hole in a dramatic final at Austin Country Club.
The 32-year-old never trailed at any point in his seven matches and was only taken beyond the 16th hole for the first time in a hard-fought semi-final victory over Japan's Hideto Tanihara.
But he was also made to work hard to secure the first prize of £1.3million in the final as Rahm, who was trying to become the youngest winner of a WGC event, fought back from five down after eight holes to take the contest to the 18th.
Rahm missed good birdie chances on the first two holes and fell behind with a bogey on the third after finding thick rough off the tee, before compounding that mistake by three-putting the next.
It looked as though the 22-year-old would escape with a half on the short fifth after his chip from the side of the green hit the pin, but he missed from four feet after conceding Johnson's birdie putt.
Another birdie on the sixth extended Johnson's lead and it would have been even bigger but for Rahm holing from 25 feet for par on the seventh after hitting his long birdie putt off the green.
However, Rahm's frustration was mounting rapidly and he kicked his driver along the ground in frustration after a wayward drive on the next led to another loss and a five-hole deficit.
Rahm, who beat American Bill Haas 3&2 in their semi-final, was handed a lifeline when Johnson bogeyed the ninth and 10th, and although the US Open champion bounced back to birdie the par-five 12th, Rahm drove the green on the short 13th and two-putted for his first birdie of the day.
A birdie on the 15th was followed by a remarkable one on the 16th, Rahm hitting his second shot seemingly straight through a tree before holing from 30 feet to get back to just one down.
Extra holes looked on the cards when Rahm drove to the back edge of the 18th green, but a terrible chip took the pressure off Johnson and he safely made par from the fringe to secure the title.
Johnson and Tiger Woods are the only players with five or more WGC titles and although Woods won an incredible 18, the former world number one failed to collect the HSBC Champions trophy in his only two appearances.
Haas beat Tanihara 2&1 in the play-off for third place, although Tanihara had the thrill of making a hole-in-one on the seventh.
Rahm appeared to have been distracted by a noise from the crowd as he hit his second shot on 18, telling Sky Sports 4: "It's not an easy chip but I could have had a 12-footer for birdie and maybe win the hole.
"For something like that to happen is really unfortunate. I understand if I miss the shot, but if something in a moment that's so quiet happens it makes it feel a little worse because it's something that I can't control.
"It feels so bad because of all the work I did on the back nine to come from five down to almost have a chance.
"It's a lot of positives to take out of this week so I'll be sad for a couple of minutes but then I'll be fine. I'm really proud of what I did, it was a great week.
"I'm thrilled I'm going to have a chance to maybe play in the Ryder Cup. It's just the beginning of the season so it's all good to come."
Johnson, who is favourite to win a second major title in the upcoming Masters, added: "This was a tough one, a tough match against Jon.
"I gave him 10 when I three-putted but that was about the only hole I gave him, he played tough. He's a great player, he's going to be a great player out here for a long time.
"I've got a lot of confidence in the game right now, feel like I am driving the ball great, I'm wedging it well. I can work on the mid-irons a bit but we can work on those next week after I take a couple of days off."
Seedings in brackets
FINAL (Sunday):
Dustin Johnson (1) bt Jon Rahm (21) 1up
SEMI-FINALS (Sunday):
Dustin Johnson (1) bt Hideto Tanihara (54) 1up
Jon Rahm (21) bt Bill Haas (42) 3&2
QUARTER-FINALS (Saturday):
Jon Rahm (21) bt Soren Kjeldsen (62) 7&5
Bill Haas (42) bt Phil Mickelson 3&1
Hideto Tanihara (54) bt Ross Fisher (47) 4&2
Duston Johnson (1) bt Alex Noren (8) 3&2
ROUND OF 16 (Saturday):
Soren Kjeldsen (62) bt William McGirt (48) 5&4
Ross Fisher (47) bt Bubba Watson (13) 4&3
Jon Rahm (21) bt Charles Howell III (61) 6&4
Phil Mickelson (14) bt Marc Leishman (28) 4&3
Bill Haas (42) bt Kevin Na (46) 1 up
Dustin Johnson (1) bt Zach Johnson (44) 5&4
Hideto Tanihara (54) bt Paul Casey (12) 2&1
Alex Noren (8) bt Brooks Koepka (20) 3&1
GROUP GAMES (Wednesday-Friday)
Players in bold qualified for last 16
GROUP 1: Dustin Johnson (1), Jimmy Walker (22), Martin Kaymer (46), Webb Simpson (64)
Wednesday: Johnson bt Simpson 5&3, Kaymer bt Walker 3&2
Thursday: Johnson bt Kaymer 3&2, Walker bt Simpson 3&2
Friday: Johnson bt Walker 4&3, Kaymer bt Simpson 3&2
Johnson wins group
GROUP 2: Rory McIlroy (2), Emiliano Grillo (30), Gary Woodland (37), Soren Kjeldsen (68)
Wednesday: Kjeldsen bt McIlroy 2&1, Woodland bt Grillo 3&2
Thursday: McIlroy bt Woodland via withdrawal, Kjeldsen bt Grillo 4&3
Friday: McIlroy halved with Grillo, Kjeldsen bt Woodland via withdrawal
Kjeldsen wins group
GROUP 3: Jason Day (3), Marc Leishman (32), Lee Westwood (49), Pat Perez (62)
Wednesday: Perez bt Day via withdrawal, Leishman bt Westwood 3&2
Thursday: Westwood bt Day via withdrawal, Perez bt Leishman 2&1
Friday: Leishman bt Day via withdrawal, Westwood bt Perez 2&1
Leishman beat Perez and Westwood in play-off
GROUP 4: Hideki Matsuyama (4), Louis Oosthuizen (27), Ross Fisher (53), Jim Furyk (57)
Wednesday: Oosthuizen bt Fisher 4&3, Matsuyama halved with Furyk
Thursday: Fisher bt Matsuyama 2&1, Oosthuizen bt Furyk 3&2
Friday: Oosthuizen bt Matsuyama 6&4, Fisher bt Furyk 4&2
Fisher beat Oosthuizen in play-off
GROUP 5: Jordan Spieth (6), Ryan Moore (36), Yuta Ikeda (41), Hideto Tanihara (60)
Wednesday: Tanihara bt Spieth 4&2, Moore halved with Ikeda
Thursday: Spieth bt Ikeda 4&2, Moore halved with Tanihara
Friday: Spieth halved with Moore, Tanihara bt Ikeda 3&1
Tanihara wins group
GROUP 6: Justin Thomas (7), Matt Fitzpatrick (31), Kevin Na (52), Chris Wood (55)
Wednesday: Thomas bt Wood 2&1, Na bt Fitzpatrick 5&4
Thursday: Na bt Thomas 4&2, Fitzpatrick bt Wood 4&2
Friday: Fitzpatrick bt Thomas 2&1, Wood bt Na 2&1
Na beat Fitzpatrick in play-off
GROUP 7: Sergio Garcia (10), Jon Rahm (25), Kevin Chappell (42), Shane Lowry (59)
Wednesday: Garcia halved with Lowry, Rahm bt Chappell 3&2
Thursday: Garcia bt Chappell 4&3, Rahm bt Lowry 2&1
Friday: Rahm bt Garcia 6&4, Chappell bt Lowry 1up
Jon Rahm wins group
GROUP 8: Alex Noren (11), Francesco Molinari (29), Bernd Wiesberger (40), Thongchai Jaidee (63)
Wednesday: Noren bt Jaidee 3&2, Wiesberger bt Molinari 2up
Thursday: Noren bt Wiesberger 3&2, Jaidee bt Molinari 5&3
Friday: Noren bt Molinari via withdrawal, Wiesberger bt Jaidee 1up
Noren wins group
GROUP 9: Patrick Reed (12), Brooks Koepka (24), Kevin Kisner (38), Jason Dufner (65)
Wednesday: Reed halved Dufner, Koepka bt Kisner 6&5
Thursday: Kisner bt Reed 1up, Koepka bt Dufner 6&5
Friday: Koepka bt Reed 1up, Kisner bt Dufner 2&1
Koepka wins group
GROUP 10: Tyrrell Hatton (14), Rafa Cabrera Bello (26), Jeunghun Wang (45), Charles Howell III (67)
Wednesday: Hatton bt Howell III 2&1, Cabrera Bello bt Wang 4&3
Thursday: Hatton bt Wang 2up, Howell III bt Cabrera Bello 1up
Friday: Cabrera Bello bt Hatton 2&1, Howell III bt Wang 2&1
Howell III beat Cabrera Bello and Hatton in play-off
GROUP 11: Danny Willett (15), Russell Knox (21), Bill Haas (47), K.T. Kim (70)
Wednesday: Kim bt Willett 4&2, Knox bt Haas 3&2
Thursday: Haas bt Willett 6&5, Kim bt Knox 3&1
Friday: Willett bt Knox 4&2, Haas bt Kim 4&2
Haas beat Kim in play-off
GROUP 12: Paul Casey (16), Charl Schwartzel (28), Ben An (51), Joost Luiten (66)
Wednesday: Casey bt Luiten 2&1, Schwartzel bt Hun An 6&5
Thursday: Casey bt An 1up, Schwartzel bt Luiten 4&3
Friday: Casey bt Schwartzel 4&3, Luiten bt An 1up
Casey wins group
GROUP 13: Bubba Watson (17), Thomas Pieters (34), Scott Piercy (43), Jhonattan Vegas (61)
Wednesday: Watson bt Vegas 1up, Pieters bt Piercy 3&2
Thursday: Watson bt Piercy 4&3, Vegas bt Pieters 3&1
Friday: Watson halved with Pieters, Vegas bt Piercy 3&1
Watson wins group
GROUP 14: Phil Mickelson (18), J.B. Holmes (35), Daniel Berger (39), Si Woo Kim (69)
Wednesday: Mickelson bt Kim 5&3, Berger bt Holmes 7&5
Thursday: Mickelson bt Berger 5&4, Holmes halved with Kim
Friday: Mickelson bt Holmes 6&5, Kim bt Berger 1up
Mickelson wins group
GROUP 15: Branden Grace (19), Brandt Snedeker (23), William McGirt (54), Andy Sullivan (58)
Wednesday: Grace bt Sullivan 4&2, McGirt bt Snedeker 2up
Thursday: McGirt bt Grace 2&1, Snedeker bt Sullivan 2&1
Friday: Snedeker bt Grace 5&4, McGirt bt Sullivan 1up
McGirt wins group
GROUP 16: Matt Kuchar (20), Tommy Fleetwood (33), Zach Johnson (50), Brendan Steele (56)
Wednesday: Kuchar halved with Steele, Fleetwood bt Johnson 1up
Thursday: Johnson bt Kuchar 2up, Steele bt Fleetwood 1up
Friday: Kuchar bt Fleetwood 4&2, Johnson bt Steele 1up
Johnson wins group