For a while, Nishikori seemed to be in a fog. Djokovic was hitting deep balls and Nishikori was unable to track them down, hitting errors. It didn’t help that his serve was not finding the target. It seemed like this would be a quick match with a 6-2 double break.
But early in the second set, Djokovic took an injury timeout to get his shoulder attended. This happened to Djokovic in Cincinnati where he might have retired against Berdych except Berdych retired before Djokovic. Djokovic retired against Murray. This seemed to energize Nishikori who started hanging in more rallies and making Djokovic work more. Djokovic also began making more errors.
Djokovic knew his hopes hinged on winning the second set, but Nishikori got to a break lead. Djokovic eventually evened up the second set and had chances to look at a second break. Alas, the match went into tiebreak where Nishikori got a minibreak and finally closed out the tiebreak.
Once Nishikori got his first break to lead 3-0, you could pretty much tell that Djokovic had decided not to win the match. He probably felt he would give a poor effort against potentially Federer so it was not worth making it to the final. In the last service game, Djokovic kept the points very short and seemed not to care if the ball went in or not. Given his retirements in the past, Djokovic seemed content to let Nishikori have his complete victory rather than retire.
This will be Nishikori’s second ATP final of the year (he lost in the Houston finals to Ryan Sweeting) where he’ll face the winner of Federer and Wawrinka. The big question is: will Djokovic play Paris now? He had already said in previous interviews that he was still not 100% despite the break.