New York - Novak Djokovic and Naomi Osaka are the defending champions at the US Open, where old rivals Serena Williams and Maria Sharapova meet in a blockbuster opening round tie on Monday.
A look at the players hoping to cause a major upset in the first round (x denotes seeded player):
Novak Djokovic (SRB x1) v Roberto Carballes Baena (ESP)
Head-to-head: First meeting
- Djokovic admits he draws inspiration from talk he could surpass Roger Federer's record for the most men's Grand Slam singles titles. Underlining the gulf between the Serb and his opening opponent in New York, Djokovic is sitting on 16 major titles while Carballes Baena has just two career main draw wins at the Slams.
An admirer of former Spain and Real Madrid goalkeeper Iker Casillas, Carballes Baena lifted his lone title on clay in Quito last year and reached the second round at Flushing Meadows in 2018. His opening round win at Roland Garros in May was just his second in seven Slam appearances.
Rafael Nadal (ESP x2) v John Millman (AUS)
Head-to-head: Nadal leads 1-0
- A year on from his stirring upset of Roger Federer in the last 16, Australia's Millman finds himself confronting a brutal first round draw up against three-time US Open champion Nadal.
The Spaniard trampled Millman for the loss of just six games in their only prior meeting, at Wimbledon in 2017, and form would dictate another routine win for the 18-time Grand Slam champion, a convincing victor at Montreal a fortnight ago.
However Millman, who was eventually stopped here in the 2018 quarter-finals by Djokovic, is hoping to spring another monumental shock in New York.
"You start off regardless of who you play, it's 0-0. It's a game for the next two, three, four hours. It's you versus the other person and anything can happen," he told ATPTour.com
Roger Federer (SUI x3) v Sumit Nagal (IND)
Head-to-head: First meeting
- Federer has played sparingly since a stinging five-set defeat by Djokovic in the Wimbledon final, and the 38-year-old hasn't triumphed at the US Open since the last of his five straight titles in 2008. For 190th-ranked Nagal, a former Wimbledon boys' doubles champion, this marks a Grand Slam debut for the 22-year-old after he rallied from a set and a 3-0 down in the final round of qualifying.
Describing himself as "just some dude from India" with a passion for Japanese culture - tattoos on his left arm depict a temple, a samurai and a lotus flower - Nagal's reverence for Federer runs deep, the youngster insisting the 20-time major winner is simply too good to be his idol.
Head-to-head: First meeting
Daniil Medvedev (RUS x5) v Prajnesh Gunneswaran (IND)
- Russian Medvedev is the hot hand on tour after pocketing his first Masters 1000 title in Cincinnati, following runner-up finishes in Washington and Montreal.
He arrives in New York among the front-runners to end the Djokovic-Nadal-Federer hegemony but must first overcome Gunneswaran, a 29-year-old left-hander from Chennai whose career was almost derailed by recurring knee fractures.
World number 88 Gunneswaran lists twice US Open champion Pat Rafter as his hero, and has appeared in all four Slam main draws this year but is still searching for an elusive victory.
It is the first time since 1998 India will have multiple singles representatives at a Grand Slam.
Naomi Osaka (JPN x1) v Anna Blinkova (RUS)
Head-to-head: First meeting
- While Osaka powered to her maiden Grand Slam crown in 2018, Blinkova broke new ground by cracking the top 100 for the first time.
The Russian, a 2015 junior Wimbledon finalist, made the third round at this year's Roland Garros, knocking out home favourite Caroline Garcia before falling in three sets to Madison Keys.
Currently ranked a career-best 84th, Blinkova will look to hand Osaka a second consecutive first round Slam exit after the top-ranked Japanese star was bundled out at Wimbledon by Yulia Putintseva of Kazakhstan.
Ashleigh Barty (AUS x2) v Zarina Diyas (KAZ)
Head-to-head: Barty leads 1-0
- Kazakh Diyas has made little impression at the majors the past couple of years, whereas Barty captured her first Slam title at the French Open in June.
Diyas, ranked 80th, won her lone title in Tokyo two years ago. Her best showing here was a third round exit in 2014, sandwiched between a pair of runs to the last 16 at Wimbledon. Away from the court she is studying for a psychology degree.
The only meeting between the two resulted in a straight-sets win for Barty at Kuala Lumpur in 2013.
