In one of the biggest upsets in Grand Slam history, John Millman defeated five-time US Open champion Roger Federer 3-6, 7-5, 7-6 (7), 7-6 (4) in the fourth round at Flushing Meadows.
The Swiss took the opening set comfortably before the Aussie struck back with a late break to claim the second set and level the match at one set all.
The world number 55 claimed a razor-thin close third set for a two sets to one lead only to see Federer take a 4-2 lead in the fourth set before the Aussie struck back one last time to claim the tiebreaker and a victory that no one will soon forget.
Federer races out to quick lead
As expected, it was the Swiss who was first off of the mark. After saving a break point in his opening service game, he broke to love and a drop-shot winner followed by an acrobatic volley winner carried him to a 3-0 lead.
Shaking off the nerves that come with the occasion, Millman held after saving a break point and was ahead 15-30 on Federer's serve before the world number two rescued the game with some strong serving.
After another hold, Federer was now in front 5-2 and had lost one point on serve the entire set after losing just seven in the prior match against Nick Kyrgios. The remainder of the set was a mere formality as the Swiss took the lead in comfortable fashion.
Millman fights back to take the second set, level the match
The Aussie was first to have chances, pushing Federer to a 14-minute hold with the Swiss saving six break points for 1-1. Millman was settling into the match, but he was broken in the fifth game as Federer took a 3-2 lead.
Winning the first point in Federer's serve in the eighth game represented success for the world number 55, but he ultimately was unable to generate any chances, the Swiss holding for a 5-3 advantage.
The tenth game would prove to change the course of the entire match as Federer took a 40-15 lead, but missed an easy forehand and dumped an easy volley to send the game back to deuce. A double fault on break point levelled the set at 5-5.
After another hold from the Aussie, he stunningly broke for a second straight time to take the second set and square the match at one set all as Federer committed 22 unforced errors in the set to go along with seven double faults for the match.
Millman grabs unlikely lead
Neither player was troubled much on serve and a laser-like backhand from Millman gave him a 3-2 lead, the Aussie well and truly in with a chance now. After another love hold gave him a 4-3 lead, the world number 55 was at 29 winners on the night.
For his part, Federer was keeping pace, employing more serve-and-volley tactics to keep the points short on a humid night in Queens. It was Millman who was holding with relative ease, but Federer was able to force a tiebreak.
The Swiss gained an early 3-1 lead only to give the lead right back as Millman pulled level at 4-4. Both players held for the next six points until Federer lost his serve to give the world number 55 an 8-7 advantage and he duly converted to take a shock two sets to one lead.
Millman completes stunning upset with second straight tiebreak win
Millman was going toe-to-toe deep into the night with the Swiss legend, but he blinked first, overhitting a forehand on break point to give Federer a 4-2 lead. Undeterred, Millman set up a break point opportunity with a forehand winner, taken when the five-time champion was long with a forehand of his own.
It looked as if Millman could find himself on the brink of victory when he went ahead 0-30 on the Federer serve, but the Swiss dug out to hold. With the set heading to another tiebreak, Federer double-faulted on consecutive points to give the Aussie a 4-1 lead.
A pair of unforced errors gave Millman five match points, Federer saving the first two, but one final groundstroke long from the Swiss sealed the Aussie's place in history and a quarterfinal date with sixth seed Novak Djokovic.