With Nishikori serving to stay in the match, Djokovic wrapped things up after two and a half hours on centre court on the first match point.
The only other times Federer has surrendered a two-set lead came against Lleyton Hewitt in Switzerland's 2003 Davis Cup semi-final loss to Australia in Melbourne, to David Nalbandian in the 2005 Masters Cup decider and to Jo- Wilfried Tsonga and Novak Djokovic at consecutive slams at Wimbledon and the US Open in 2011.
Nishikori, who had won only two matches in 15 meetings with the 12-time major victor, broke for 1-0 in the fourth but was broken straight back.
After seeing off big servers Kyle Edmund and Karen Khachanov, he faced Nishikori, who had recovered from his own serious injury to hit peak form in reaching his first Wimbledon quarter-final.
However, Nishikori was prevented from launching a comeback as Djokovic, a three-time Wimbledon champion, regained his composure and managed to grind out wins in the third set (6-2) and in the fourth set (6-2) to set up a semifinal match against Juan Martín del Potro or Rafa Nadal.
Djokovic overcame a series of rows with the chair umpire to record a 6-3 3-6 6-2 6-2 victory over Japan's former US Open finalist.
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In theory, some European companies could benefit, jumping into market niches if Chinese businesses are kept out of the USA market. But eventually those costs will take their toll on the average wallet, and it likely won't be simply because of these tariffs.
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Perez was rushed to Cooper University Hospital in Camden, where he was quickly admitted into the intensive care unit. With the prognosis still unknown, the Perez family is praying Angel leaves the hospital with his life and limbs.
Na wins by five at Greenbrier for first victory…
Tag Ridings (Arkansas Razorbacks) tied for 27th at 11 under, while Sebastian Cappelen (Razorbacks) tied for 41st at 8 under. Everything was going my way, and it was nice to have that big lead going up to the last hole and enjoying the moment.
Novak Djokovic accused a Spanish match official of "double standards".
Political tensions have existed between the neighboring countries dating back to the break-up of Yugoslavia, so the 12-time Grand Slam winner's comments were met with angry posts on social media from the Serbian government official. But then the Japanese player, world number four in March previous year, survived four break points early in the second set to level. "I've been building in the last couple of weeks and my level of tennis is going up", he said.
"I am peaking at the right moment". But he grew frustrated after failing to capitalize on three straight break points in the third game of the second set and was given a code violation after slamming his racket into the ground.
"To be honest, I thought it was unnecessary to get a warning".
"It didn't harm the grass".
I am backing Croatia.I know who I would like to lift the trophy."You think I ruined the court by tossing the racket two metres behind the baseline?"