Or was it the court?
For only the fifth time (and third in 269 Grand Slam matches), Federer squandered a two-set lead.
Federer had not dropped a set in his serene run through to the last eight at the All England Club, and the defending champion appeared poised for a relatively routine win when he went match point up in the third set.
And with Federer dumped out of Wimbledon, the competition has opened up and paved the way for his arch rival - Rafa Nadal - to claim his third title at the All England Club.
With the scores deadlocked at 11-11 in the final set, and no obvious break in serve forthcoming, Anderson profited as Federer started to show signs of strain.
And he didn't stop there.
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Although Pompeo called the meetings "productive", North Korea said the lack of emphasis on security guarantees was "regretful". The Defense Department estimates there are up to 5,300 sets of US service member remains still somewhere in North Korea.
Even though he was two sets down and facing match point on Wednesday, Anderson insisted he never gave up hope.
But he found himself in even more unfamiliar territory despite racing through the first set in 26 minutes, with an inspired Anderson's relentless, thudding serve eventually overpowering the 20-time grand slam victor.
Roger Federer is out of Wimbledon, which means that half the viewership of the grass-court Grand Slam is now looking for something else to watch on television.
Vanquished champion Roger Federer plans on returning for another tilt at Wimbledon glory next year - but don't call it unfinished business.
"Honestly, I'm not sure", the 20-times Grand Slam champion said when asked where it had all gone wrong. After that I never really felt exactly 100 %. "Then you have moments in the match where you rise to the occasion and play very well". If I want to beat him, I have to come to the net very often and play hard with my forehands, with my backhands, and try to take all the chances'. The South African was just a better player and better competitor on the day: he hit 28 aces, 65 winners and 31 unforced errors compared to Federer's 16 aces, 61 winners and 33 unforced errors.
Kevin Anderson (8) narrowly defeated Gael Monfis in four sets to reach the quarterfinals.
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Now I think a lot of questions have been answered in saying that this is a team, not a group of individuals. Martinez added: "Thierry has brought something we didn't have".
As Kevin Anderson secures South Africa's first shot at a Wimbledon final in more than 30 years, the Sports Minister has congratulated him for his stunning win.
Novak Djokovic's clash against Kei Nishikori went more to script and saw the Serb advance to his first Grand Slam semi-final in nearly two years following a confident 6-3, 3-6, 6-2, 6-2 win. "The more I can just treat it like another tennis match, the better for me", Anderson said earlier in the week.
The Spaniard came through a mammoth encounter with Juan Martin del Potro yesterday, making the final four for the first time in five years after a five-set clash which spanned almost five hours.
When he finished runner-up to Rafael Nadal at the US Open past year, he was the first South African man in a Slam final since Curren at the 1984 Australian Open. "I played only once in first four matches on Centre Court".
From there, the tall and powerful Anderson kicked on whilst Federer stalled. I was able to, you know, hold serve throughout.
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Strzok told the Committee that FBI attorneys instructed him not to answer any questions about the ongoing investigation. David Cicilline , D-R.I., cut him off and asked him to withdraw the assertion that Strzok had lied.
"I think the first warning was unnecessary", said Djokovic, who was sanctioned in the second set for spearing his racquet into the court.
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