US Open: Federer in Djokovic half, Serena vs Sharapova in first round clash

Djokovic could face Federer in the semi-finals and Rafael Nadal in the final

TENNIS-US-OPEN Novak Djokovic of Serbia celebrates his victory over Juan Martin del Potro of Argentina after their 2018 US Open men's singles final match | AFP

Top-ranked defending champion Novak Djokovic could face Roger Federer in the semi-finals and Rafael Nadal in the final, while the women's first round is set for a blockbuster of Serena Williams vs Maria Sharapova under the US Open draw unveiled Thursday at Flushing Meadows. 

Djokovic, who defeated Federer last month in an epic Wimbledon final for his 16th Grand Slam crown, had the 20-time Grand Slam champion and third seed dropped into his half of the draw. 

Second seed Nadal, who won his 18th Grand Slam title at this year's French Open, has Austrian fourth seed Dominic Thiem on his side of the bracket. 

Djokovic will play his first round match against Spain's 76th-ranked Roberto Carballes Baena. 

Federer will open against a qualifier as will Japan's seventh-seeded Kei Nishikori, also in his quarter of the draw. 

Nadal's first US Open match will be against Australia's 61st-ranked John Millman, who shocked Federer at the tournament in 2018, while fourth-seeded Thiem's opener will be against Italy's Thomas Fabbiano.

In women's clashes, Williams will begin her quest for a seventh US Open title and record-tying 24th Grand Slam victory against long-time rival Sharapova.

Williams has dominated the Russian star in their head-to-head rivalry, winning 19 times with only two defeats, including their past 18 meetings, most recently at the 2016 Australian Open quarter-finals, although Sharapova advanced by walkover against Williams in the fourth round at Roland Garros last year.

Eighth-ranked Williams is looking to match the all-time record of 24 Grand Slam singles titles won by Margaret Court when the year's final major championship gets under way Monday.

The 37-year-old American has dropped her past three Grand Slam finals appearances, including last month to Simona Halep at Wimbledon and last year to Japan's Naomi Osaka at the US Open after a controversial game penalty for her tirade at umpire Carlos Ramos.

Tournament officials have said Ramos will not work any matches involving Serena or Venus Williams, who could not face her sister until the semi-finals, being in the same draw quarter as Czech third seed Karolina Pliskova.

Serena was placed into the same quarter as Australian second seed Ashleigh Barty, the reigning French Open champion whose first match is against 77th-ranked Zarina Diyas of Kazakhstan.

Top-seeded Osaka opens against Russia's 93rd-ranked Anna Blinkova and could face a third-round date against 15-year-old American Coco Gauff, who eliminated Venus Williams in the first round at Wimbledon in a run to the last 16 in her Grand Slam debut.

Romania's fourth-seeded Halep, coming off her second Grand Slam title, opens against a qualifier and could face a semi-final against Osaka, who defends a Slam crown for the first time.