Rory McIlroy and Xander Schauffele played 72 holes together this week in Shanghai and then needed one more to decide the WGC-HSBC Champions.
A closing birdie from Schauffele in regulation knotted the two at 19 under par and sent them back to the 18th tee.
"After starting 10 under through the first two days, I thought going bogey-free over the weekend would probably be enough to get the job done," McIlroy said.
"But, you know, I've played 73 holes this week with Xander, and I have to give credit to him. He's battled the flu all week and he's played unbelievably well considering how he's been feeling."
After drawing the honor on the tee, McIlroy, who had just made par on 18 to close out a final-round 68, laced his drive down the middle of the fairway, setting him up to go at the par-5 green in two:
With Schauffele having already laid up from the left rough, McIlroy then hit this 4-iron approach from 223 yards to 25 feet:
"There's a sign just left of this little walkway off the back of the 18th and I picked that out and just said, 'Make a good swing,'" McIlroy explained minutes later on the green. "And if I made a good swing on it, hopefully the wind would catch it and bring it back a little bit to the right. It was a perfect number for a 4-iron, just back into the wind a little bit.
"You've got to take everything out of the equation and just hit the golf shot."
After McIlroy's eagle try trickled by the hole, and Schauffele's 12-footer for birdie wouldn't drop, this was all McIlroy had left to close out his fourth win of 2019:
"This 18th [hole] has been good to me over the week," he acknowledged. "I had an eagle here on Friday, I made a great birdie yesterday, got lucky in regulation not to go in the water [off the tee], and then it was a relief to hit those two shots in in the playoff."