Sloane Stephens has broken Daria Kasatkina in the second set.

The American is now a set and a break to the good as she closes in on an all-American semi-final with Madison Keys.

She leads 6-3 3-1 against the Russian 14th seed.

But just as the pressure is eased, Djokovic sticks it right back on. Second set point.

Cecchinato saves it. He runs around the shot to get it onto his forehand, and it proves a good decision as Djpokovic can only send his next shot into the top of the tape. Set point wasted. Deuce.

Djokovic has a set point.

Cecchinato is not put off by that warning by bringing us to 30-30.

Marco Cecchinato gets a warning for coaching, and looks absolutely baffled. His eyes were on the ball just as he was about to serve. Seems a harsh one. 15-30

Cecchinato sinks a backhand return into the net. Djokovic needs three more points for the set.

Make that two after he sends the Italian wide and he can only dump another one into the net. 0-30

Fired up, pumped up and it works for Novak Djokovic. He takes the game for a 6-5 lead, so once again Cecchinato has to serve to save the second set.

Marco Cecchinato is 72nd in the world, well, he was before this tournament started, and he is having a day to remember sprinting up to the net to bury a forehand for 0-15.

But a pumped up Novak Djokovic wins two points in a row and lets out a huge scream after moving 30-15 ahead. Fired up.

A warning for coaching comes Djokovic's way, after picking up some hand signals from his team as Cecchinato seals out the game.

Novak Djokovic has only had one break point against the Cecchinato serve. but we are now at deuce. The Serb two shots from the set and 1-1.

You have got to be doing something right to keep fooling Novak Djokovic with the drop shots. That is what Marco Cecchinato is doing, and earns a thumbs up gesture from the Serb, appreciating a good shot and showing some class. 30-15

A routine hold of serve for Novak Djokovic means Cecchinato is now serving to save the second set after taking the first.

Sloane Stephens has taken the first set against Daria Kasatkina.

If Stephens wins it will set up a semi-final against fellow American Madison Keys, who she beat in last year's US Open final.

No messing about from that Novak Djokovic return. His opponent gets his racquet on to it, but can only send it at some pace into the stands.

But that is the only bright spot for the Serb in that game. 4-4. On to the next one.

Some delightful shots from Marco Cecchinato, playing the biggest game of his career, but it all counts for nothing on the scoreboard.

Novak Djokovic had to dig deep in that game, but saved two break points and we are still with serve in the second set.

Two break points come, two break points go.

A great, great rally. One of the best of the tournament. The backhand earlier this game was good, maybe this one is better from Cecchinato. Djokovic keeps it alive though before the Italian finishes it off with a deft drop shot. Two break points. 15-40

A beautiful backhand down the line from Marco Cecchinato takes him to 0-30 on the Djokovic serve, before the Serb bolts down an ace, his second of the match.

Djokovic pulled it back to 40-30 but then sends a return long and that is another game in the books for the Italian. 3-3 in the second set, Cecchinato one set up.

That is now 13 unforced errors from Djokovic, compared to 11 for Cecchinato.