With the open nature of the course, DeChambeau could “see where [McIlroy] was almost on every hole from 13 on in” from his position in the group behind.
“I even saw on 10 where he made birdie,” said the American, who now plays on the LIV Golf circuit.
“I’m like, ‘oh, man, he’s gunning, he’s going for it’. So I had to put my foot on the pedal and push down pretty hard.
“I could hear ‘Rory, Rory’ chants. That was fun because it gave me the knowledge of what I had to do.
“There was also a lot of, ‘go USA, go Europe’. It was a fun battle between us.”
DeChambeau engaged with fans throughout the week both during and after his rounds and his social media presence means he is now one of the game’s most popular players.
When the winning putt dropped, he mouthed “can you believe that?” to the TV cameras, before bouncing around the green with his caddie and support team.
After the presentation, he charged into the group of fans lining the 18th fairway, honouring his pledge to allow them to touch the trophy, before posing with it for photographs in what will surely now be known as ‘DeChambeau’s bunker’.