Djokovic came back strongly after the third set debacle, producing an outstanding performance, the World No.1 sent winners from all angles and beat World No. 2 Nadal 6-2, 6-4, 6-7 (3), 6-1 in a match chock-full of lengthy and fascinating points to earn the first U.S. Open championship of his career.
There's no doubt Djokovic will be the fresher of the two when they meet on Friday, after Del Potro took a lot out of Nadal.
Today sees the men's singles semi-finals take place at Wimbledon, and looking forward to two excellent match-ups, is our tennis columnist, Dan Weston.
Whoever wins will set the final to face either Ralf Nadal or Novak Djokovic.
World number one Nadal, the 2008 and 2010 champion at the All England Club, trails Djokovic, the 2011, 2014 and 2015 victor, 26-25 in a rivalry which began at Roland Garros 12 years ago.
For his part, Djokovic is eyeing a 13th major after making the semifinals of a Slam for the first time since finishing runner-up at the 2016 US Open.
"He is one of the more complex players that I ever saw on our sport".
While Trump would have been a distraction in the royal box - especially if the wind were to cut through his hair spray - the 15,000 sunbathers on Centre Court instead have a double bill of Isner and Anderson at 1pm, followed by the main course, Rafael Nadal and Novak Djokovic. He seems to have returned to form, as he has been excellent at Wimbledon.
The Argentine next faces two-time champion Rafael Nadal, who has reached the Wimbledon quarterfinals for the first time since 2011.
Wayne Ferreira, meanwhile, reached the quarter-finals of Wimbledon in 1994 but since then there has been little to celebrate from a South African perspective. until now. Because of the length of the first match, that semifinal will be played with the roof closed. I remember chatting to Andy Murray before the tournament and we felt that... Both players hold well over 90% of the time on grass, as well as being below-average returners, and tiebreaks are again likely.
Anderson eliminated eight-time Wimbledon champion Roger Federer in the quarterfinals. "I'm not going to change that now", said the American.
It's a really tough match to call but I think Nadal will come through in four sets.