What it means: Castro carried a lead into the infamous "Green Mile" closing stretch, but bogeys on Nos. 16 and 17 gave Hahn a one-shot advantage on the 18th green. When Hahn three-putted, it allowed Castro to force overtime with a 6-foot par putt on the final green, but he promptly put his tee shot into the water on the first extra hole. It let Hahn make par to secure his second career win despite entering the week on a string of eight straight missed cuts.
Round of the day: McIlroy started the day eight shots off the pace, but he made up plenty of ground with a 6-under 66. The defending champ rolled in eight birdies, including six across his first 11 holes, and despite a closing bogey he left Charlotte with his sixth top-10 finish in seven trips to Quail Hollow.
Best of the rest: Mickelson began the round alongside McIlroy, and he kept pace with a 66 of his own that led to a T-4 finish. Mickelson had five birdies and an eagle against just a single bogey, earning his seventh career top-five finish at an event where he is a perennial contender but has yet to hoist the trophy - one that might have been his were it not for a quadruple bogey to close his third round.
Biggest disappointment: Fowler led by one entering the day and earned his first PGA Tour win here in 2012, but a repeat performance wasn't to be as he struggled to a 2-over 74. Fowler bogeyed two of his first four holes, then lost ground when his approach to the par-5 seventh hole found the water, leading to a costly double bogey. Fowler, like McIlroy and Mickelson, ultimately missed the playoff by two shots.
Shot of the day: William McGirt created some early noise with an ace on the par-3 second hole from 178 yards. The shot helped McGirt to a closing 68 that gave him a share of 17th place at 2 under.
Quote of the day: "You just start questioning yourself. Are you good enough? Will it ever happen again?" - Hahn, who hadn't made a cut since the Waste Management Phoenix Open prior to this week.