Roger Federer branded his performance as "average" after missed opportunities cost him in his epic Wimbledon quarter-final loss to Kevin Anderson.
Federer looked to be easing towards the last four after taking the opening two sets against the eighth seed, and even had match point at one stage in the third.
But Anderson survived the scare before incredibly turning the match around, eventually emerging victorious from an absorbing battle of wills as he prevailed 2-6 6-7 (5-7) 7-5 6-4 13-11.
The victory saw him become only the third man to come from two sets down to beat Federer, following in the footsteps of Jo-Wilfried Tsonga and Novak Djokovic, leaving the Swiss to ponder how he allowed the defence of his title to come to an end.
Asked if he knew where he lost control, Federer told a media conference: "I guess there was definitely a moment at some point. Is it missing match points? Is it getting broken at five-all after that? I'm not sure.
"That could have been a key. Could have been a key later. There's a lot of little points here and there that always make a difference in the outcome of a match. I don't think this one naturally you can pinpoint exactly, except my match points.
"I was very happy that I got off to the right start of the match, was able to take control somewhat of the game. I just don't know exactly how I couldn't create more opportunities once the third set came around.
"I think I had chances, I'm not sure exactly how many. But then fourth and fifth, obviously the fifth was long, that's like two sets, the fifth.
"He was consistent. He was solid. He got what he needed when he had to. Credit to him for hanging around really for that long.
"It's just not one of my best days, but they don't happen very often either. It's one of those average days you have to try to win the match, and I just couldn't get it done. So it's disappointing."
Put to Federer that the loss gives him unfinished business to come back to the tournament in 2019, he responded: "Of course, the goal is to come back here next year. I wouldn't call it unfinished business. I felt like I did some good business here in the past already."
|Warburton retires: Gatland salutes Wales and Lions great|
|Sturridge determined to stay at Liverpool|
|Mbappe is an alien – Varane|
|Warburton retires from rugby|
|India to assess Bhuvneshwar as Bumrah makes Test squad|
|Injured Craddock passes $100,000 in donations at Tour de France|
|WATCH: Perez taunts team-mate after audacious training goal|
|Alison Becker tweets ´I´m joining Liverpool´... but all is not as it seems|
|Notorious Carnoustie holds fond memories for legendary Watson|
|Rooney refused to be ´dead weight´ at Everton|
|The Open 2018: Molinari, Rahm and the in-form contenders at Carnoustie|
|Marsh interested in Australia leadership roles|
|United can challenge City for Premier League title, says Rooney|
|MLB All-Star 2018: Seven things you missed at Midsummer Classic|
|American League win home run-filled MLB All-Star game|
|Dragons lure Sims from Broncos|
|Cassano: Ronaldo like Nadal, Messi like Federer|
|Lakers´ Ball undergoes successful knee surgery|
|´We kill them, Messi or no Messi´ - Pogba´s pre-Argentina World Cup speech revealed|
|Cardinals suspend GM Keim for five weeks after DUI|
|Dalic: I can coach Brazil or Barca but Croatia my favourite|
|Warriors coach Kerr extends contract|
|I´m ready to bust him up - Miller calls out Joshua after New York confrontation|
|CAF Champions League Review: ES Tunis and TP Mazembe set the pace|
|Mixed day for seeds in Newport as Muller progresses|
|Rams sign Cooks to five-year extension|
|Cowboys’ Randy Gregory reinstated by NFL|
|Verdasco survives Swedish Open scare as Paire is picked off in Umag|
|US Open announces record prize fund for 2018|
|Stosur wins battle of former grand slam champions in Gstaad|
|Emery is Arsenal´s best signing, says Pires|
|Brewster commits to Liverpool with long-term deal|
|Panama boss Gomez steps down after World Cup|
|No Chelsea agreement for Golovin, claims CSKA president|
|Root looks right at home as England ease to series victory|
|Brighton sign Mali midfielder Bissouma from Lille|
|Kaka backs Brazil boss Tite after ´excellent´ World Cup|
|Alaphilippe the toast in France as Van Avermaet increases Tour lead|
|Shkupi 0 Rangers 0: Gerrard´s men advance despite dour draw|
|Khazri ends Sunderland nightmare as Saint Etienne swoop|
|The Open 2018 diary: Rose lets Rio go as Rahm goes ´Lefty´|
|Lampard raids Chelsea and Liverpool in Derby double swoop|
|Balotelli returns to Nice training after Marseille talks stall|
|Owens wants to play in the CFL, says agent|
|I don´t like thinking too much - Johnson|
|Toulon president fined as French club receive suspended points penalty|
|Top of the flops - Mickelson plays exquisite trick shot over man´s head!|
|Kerber targeted Wimbledon after 2017 disappointment|
|England´s World Cup heroes given dedicated parking spots|
|Insigne prefers Messi to new Juve star Ronaldo|
|Koepka enjoys playing with a chip on the shoulder|
|Ryan Hall to leave Leeds Rhinos amid reports of NRL move|
|Hamann slams Lahm for Low criticism|
|Hart named in Manchester City squad for United States tour|
|F1 Raceweek: Leader Vettel heads home|
|Unfair to pin Brazil blame on Neymar, says Kaka|
|Thomas and friends ´want to beat each other´s brains in´|
|Woods´ love for links fathered at Carnoustie|
|Confident Rose targets tournament wins and number one spot|
|Hallgrimsson leaves Iceland post|
|Australian Open to consult players over fifth-set tie-breaks|
|Daley´s coming home - Ajax rewrite Three Lions anthem|
|Woods: Open my best chance at winning another major|
|Blind completes Ajax return from Manchester United|
|I belong at the top, says Anderson|
|Leaving Madrid was my biggest regret, Panucci warns Ronaldo|
|Folau in no rush to settle future amid Reds rumours|
|Degenkolb: I need two or three secretaries to manage congratulations!|
|Harrington v Garcia: When winning makes life tougher|
|Mafi and Timani fined by Rebels|