The two biggest names in men's golf over the past two decades faced off Friday for the first time in match play, with Mickelson edging his old rival Tiger Woods on the fourth extra hole.
"I was half a second from giving him that putt because he always makes those", Mickelson said to his brother, Tim, who was his caddie.
Woods said he enjoyed the match, even if he was on the losing end.
Mickelson was one up going into the turn after Woods had three-putted the previous hole to make his second bogey of the day, but Woods did at least birdie the 11th and 12th to edge in front for the first time.
"The Match", a $9 million one-on-one showdown between golf icons Tiger Woods and Phil Mickelson is officially underway.
Tiger Woods of the United States looks on during the final round of the 2018 Masters Tournament at Augusta National Golf Club on April 8, 2018 in Augusta, Georgia.
In an innovative addition to the one-off contest, Woods and Mickelson will pose in-round games including closest-to-the-pin and longest-drive challenges.
Mickelson said to Woods after the match: "Just know I will never let you live that down".
The landmark golf event - produced by Turner Sports after U.S. media company WarnerMedia signed a worldwide rights deal - is thought to be the first televised pay-per-view golf product in USA history, with a recommended retail price of US$19.99 announced by Turner. Turner and Bleacher Report representatives sent out links on social media allowing people to view it for free on their computers and mobile devices. -Phil to customers for the same amount, in a pickle: How could they force viewers to pay if they ultimately could have saved 20 bucks and still watched online?
But since their heyday in the late 1990s and early 2000s, however, both Woods and Mickelson have been in steady decline. But Mickelson came right back to birdie - his only won hole with a birdie until the last one - giving you the sense that perhaps the closing holes would produce the fireworks. Mickelson then squared it with a birdie on the par-3 13th and retook the lead when Woods bogeyed the par-4 15th. Both birdied the par-5 18th and then parred the first playoff hole before it went to the par-3 extra hole - which was pitch shots off the practice putting green - that they kept playing until there was a victor. A match sorely lacking drama got some when Woods chipped in for a birdie at the 17th.
While both the 48-year-old Mickelson and the 42-year-old Woods are past their prime, Friday's meeting between the 19-time major winners still provided some entertaining golf. Woods practiced at the course only before a news conference Tuesday.