Shanghai: Roger Federer blazed into the Shanghai Masters semi-finals with a 6-4, 7-6 (7/4) victory over Kei Nishikori as the Swiss great's title defence belatedly caught fire on Friday.
Three-time Shanghai Open victor Djokovic stormed past German Alexander Zverev 6-2 6-1 in Saturday's earlier semi and claimed the world number two ranking from Federer.
And Coric, a semi-final victor against Roger Federer, lost all composure at the start of the second, sending a simple volley well wide of an open court to hand Djokovic another break.
The 37-year-old Swiss will next play 21-year-old Borna Coric, who overcame Australia's Matthew Ebden 7-5, 6-4.
"It was one of the best matches of my life", Coric said. Djokovic saved set point in the opener before taking control of the tie break and the second set to dump out the South African seventh seed.
The 21-year-old, now ranked 19th, will enter the top 15 of the ATP rankings for the first time after he competes against Novak Djokovic in Sunday's final. But even in defeat, both Federer and Zverev have qualified for the season-ending ATP Finals, featuring the world's top eight players on November 11 in London.
Touted as a potential future multiple Grand Slam victor, fourth seed Zverev eased past Kyle Edmund to reach his first Shanghai semi-final.
Speaking in Shanghai, the 31-year-old Djokovic said there was "confusion" with the two competing events coming so close together and being so similar.
Normal order appeared to have been restored when the 20-time Grand Slam champion comfortably claimed the first set against Bautista Agut.
But the world number three exploded back to life mid-season, winning Wimbledon, the Cincinnati Masters and US Open.
Federer had to play catch-up in the tie break and said afterwards that he was relieved to avoid another three-setter. He's bidding to win a record fourth Shanghai title this week.