Novak Djokovic Battles Kay Nishikori To Reach The Fourth Round Of The US Open.

The world number 1 overcame a loose first set 6-7 (4-7) 6-3 6-3 6-2 and beat the Japanese from  the 17th time in a row. The 34-year-old Serbian is eyeing a record 21. Men's Grand Slam title.

He then meets American Jenson Brooksby after the Russian wildcard beat Aslan Karatsev in five straight sets as the 21st seed. Brooksby, number 99 in the world, came from behind to win 6-2 3-6 2-6 6-3 6-3 and became the youngest man in the United States to reach the 2002 fourth round after Andy Roddick's US Open was born.

Top seed Djokovic received mixed feedback from the New York crowd but appeared to have won it by the last points. Several times, he asked them to make more noise, put his ear to the fans, and not do his traditional holiday "show of love" in the stands. However, after his post-match interview.

Nishikori fought hard but only managed to overturn two of his 13 through chances. One of those breakthroughs came as Djokovic led 5-3 in the third set, but the Serb reacted immediately and finished fourth regularly to end the game.

"I don't think I started very well, but he surprised me today with his level," said Djokovic. German qualifier Oscar Otte reached the fourth round of a Grand Slam for the first time with victory over Italy's Andrea Seppi. World number 114 Otte, who lost one match point in her first two qualifiers, won 6-3 6-4 2-6 7-5.

He will face Wimbledon finalist Matteo Bertini, who will have to work hard against Belarusian Ilya Ivashko. The Italian, seeded in sixth place, hit 69 winners after winning 6-7 (5-7) 6-2 6-4 2-6 6-3. Jannik Sinner of Italy 13th beat Gael Monfils in five sets and beat a fight by France to win 7-6 (7-1) 6-2 4-6 4-6 6-4. Sinners meet Germany's fourth seed Alexander Zverev, who advanced 3-6 6-2 6-3 2-1 with a thigh injury following the failure of his opponent Jack Sock.

The American won the first set convincingly but suffered injury problems from the second set onwards. After being defeated in the fourth set, he finally gave up, knowing there was no turning back. Lloyd Harris of South Africa continued his fine form with a 6-4 6-4 6-4 win over Wimbledon semifinalist of Canada Denis Shapovalov. He will then play Riley Opelka after the American beat Nikoloz Basilashvili of Georgia 7-6 (7-5) 6-3 6-4.