Novak Djokovic felt he was a different player to the Wimbledon victor of old but comparisons were inevitable on Wednesday as the Serb rolled into the semi-finals for the first time since 2015.
With his 24th seeded opponent saving three break points to hold serve at 2-1, Djokovic bounced his racket off the baseline in frustration and then seethed after he was given a code of conduct warning.
The big Argentine is looking to set up a mouth-watering quarter-final against Rafael Nadal, looking to avenge his defeat by the Spaniard, seeded second at Wimbledon, in the French Open semi-finals last month.
After breaking Djokovic's first serve to get off to a promising start in the fourth set, Nishikori was immediately relinquished of his lead as Djokovic broke back once and then again.
"It motivates me to do extremely well here because I don't want to sit here and explain my loss".
"Sometimes you don't feel good, and you try your best. I'm enjoying my Wimbledon journey".
It was performance of resilience and resolve from the former number one, reminiscent of the player who held all four Grand Slam titles two years ago.More news: Chelsea finalising £50m double swoop deals for Napoli’s Sarri and midfielder Jorginho
When Del Potro sent a forehand rifling down the line to take the third set, it seemed Nadal might be following Federer out of the tournament, but the World No.1 recovered superbly to triumph 7-5 6-7 (7/9) 4-6 6-4 6-4 and keep alive his hopes of an 18th Grand Slam title. I know, as everything in life, we are evolving. "It didn't harm the grass".
Asked if he had expected to be switched to Centre, where matches can go on till 11pm under floodlights, the three-times Wimbledon champion said: "Of course, it's always an option".
Big-serving South African Kevin Anderson came back from two sets down to edge past top seed and defending champion Roger Federer 2-6 6-7 (5) 7-5 6-4 13-11 and reach his first Wimbledon semi-final. Frustrated, Djokovic threw his racket to the floor and received a warning from the umpire.
"So I think it's not fair but it is the way it is, in the mix of emotions and a tough match it happens".
"Do you think or not?"
"(Nishikori) even threw the racquet in the fourth set. The two began dating long before Djokovic became a household name, and got married in Montenegro in 2014 right after he won Wimbledon. His latest foray into the final four of Wimbledon is just another addition to his now 32 Grand Slam semifinal appearances, now second on the list behind Roger Federer.
"I like the level of tennis that I'm playing on right now", Djokovic said.