After months of recovery from elbow surgery and a drop in his level of play that sent him tumbling down the rankings, Djokovic, 31, has recovered in the second half of the year to win titles at Wimbledon, the US Open and the Cincinnati Masters.
And even though Federer provided some early resistance in Coric's match-winning service, the 20-time grand-slam champion could not find a breakthrough to survive. Touted as a potential future multiple Grand Slam victor, fourth seed Zverev eased past Kyle Edmund to reach his first Shanghai semi-final.
The 21-year-old German, regarded as one of the finest prospects in tennis, said that he expects other high-ranking players to follow suit.
He is desperate to take injured Rafael Nadal's number one spot before the year is out, and on this evidence, he will.
"I just feel like the date of the Davis Cup is really bad, especially for the top players", said Djokovic, echoing the strong sentiments of Zverev a day earlier.
A miss-hit Federer forehand gifted Coric the opening break of the second set for a 2-0 lead, before Coric pulled off an excellent lob and smashed an ace down the tee to move clear at 5-3.
Coric finished off Federer in style with the final two points an ace and a sizzling forehand crosscourt victor.
Edmund will play fourth seed Alexander Zverev in the last eight, after he beat Australia's Alex de Minaur 6-1 6-4.
One player who will not be in the quarter-finals is Juan Martin del Potro after he hobbled out of the tournament. There is still a lot more tennis going on till the end of the year. "It's going to be definitely a close match". "I was telling myself, particularly tonight I can not do this (lose) because they were there, but I don't know how much I draw from that, quite honestly".
"It's always easier to get there - but then staying there is always the tougher part".