NEW YORK — Three weeks before the U.S. Open began, 24-year-old Kei Nishikori had a cyst removed from his right foot during a procedure in Charlotte, N.C.He flew home to Florida to begin his recovery and was officially listed as questionable for the U.S. Open. Now, a month later, Nishikori has made history by becoming the first man born in Asia to reach a Grand Slam final after he stunned world No. 1 Novak Djokovic, 6-4, 1-6, 7-6 (4), 6-3 in the semifinals in 90-degree heat and extreme humidity in Arthur Ashe Stadium. The match lasted 2 hours, 52 minutes. “Before come to New York, I wasn’t really sure I should come to New York or should I do rehab more in Florida,” Nishikori said on CBS of his foot procedure. “[Michael Chang] said come and play the first couple matches and you might feel good.” Chang, the former French Open champ and U.S. Open runner-up, is Nishikori’s coach. Turns out he knew a little something. In the span of six days now, the Japanese sensation and No. 10 seed has taken out the Nos. 1, 3 and 5 seeds at the Open. “I feel the support from Japan, even from the TV,” Nishikori said on court. “It’s 4 o’clock in the morning but I hope a lot of people are watching.” Nishikori, who will play either Roger Federer or Marin Cilic in Monday’s final, became the first Japanese man since 1934 to reach a Grand Slam semifinal and the first since 1918 to reach the semis of the U.S. Championships. The start of the Federer-Cilic semifinal was delayed by rain. “This is definitely huge for Japan,” said Djokovic, who was bidding to win his eighth Grand Slam title. “It’s a big country of 100 million people. It can definitely be a great encouragement for tennis in that country…Playing finals of a Grand Slam and now playing for title, is definitely something different. He has gotten to another level and I’m sure that people will praise him.”Coming into the Open, Nishikori had career earnings of $5,441,044, as Robert Raiola pointed out on Twitter. He will get $3 million if he wins. The Big Four of Djokovic, Federer, Rafael Nadal and Andy Murray have won 36 of the last 38 Grand Slam events, with only Juan Martin Del Potro at the 2009 U.S. Open and Stan Wawrinka at the 2014 Australian Open interrupting that streak. Now Nishikori could become just the third non-Big Four member to win a major since the 2005 French Open. Meantime, Federer could theoretically win the Open without having to play Djokovic, Murray or Nadal ( who skipped the tournament with a wrist injury). Djokovic won’t play in the Flushing Meadows final for the first time since 2009. He won the event in 2011 and was playing in the semifinals of a Grand Slam for the 17th time in his last 18 majors. Nishikori’s accomplishment is all the more impressive considering he played back-to-back five-setters in the fourth round against No. 5 Milos Raonic and in the quarters against No. 3 Stan Wawrinka, the Australian Open champ. Raonic kept Nishikori on the court until 2:26 AM Tuesday, and he did not go to bed until 5:30 am that day. He was back on the court in extreme heat on Wednesday in another five-setter against Wawrinka, but Nishikori had two full days to rest after the win. Nishikori charged out of the gate, breaking Djokovic twice in the first set en route to taking a one-set lead. He hit his groundstrokes deep and into the corners, putting the Serb on the defensive.But Nishikori seemed to succumb to the humid conditions in the second set, when he was broken twice, and it appeared Djokovic might cruise from there. Coming into the match, Nishikori had spent 13 hours, 34 minutes on court, compared with 10 hours, 5 minutes for Djokovic. The many hours on court seemed liked they might finally catch up with Nishikori. “Same for both players,” Djokovic . “It was not easy to play in these conditions, but also he had more hours spent on the court. So it’s no excuse.” Djokovic added: “I expected him to be able to play another five-setter because he had two days off. He hasn’t played before this tournament, so he had a big break. He could prepare himself for this tournament.” The match turned in a third-set tiebreak when Nishikori raced out to a 5-2 lead, and then took advantage of three straight mini-breaks by Djokovic, who hit a forehand long on set point to give the Japanese a two-sets-to-one lead. Nishikori then broke Djokovic in the first game of the fourth set and held serve after going down 0-40 in the second game for a 2-0 lead. The match ended when Djokovic sailed a forehand long on match point. “He played some great tennis,” Djokovic said. “I congratulate him for the effort. He was the better player today.” A player who was questionable for the U.S. Open just three weeks before it began.