Novak Djokovic is being coy about his plans for the Australian Open, Olympic champion Alexander Zverev is celebrating the best season of his career, while the tennis world reaches out for Peng Shuai.
The first match pitting seeds up against each other is set, with Victoria Azarenka and Garbine Muguruza to face off in an intriguing third round clash of former world No.1s and Grand Slam champions.
Kicking off play on Louis Armstrong Stadium, last year’s beaten finalist Azarenka proved too strong for Italian Jasmine Paolini, winning in straight sets before Muguruza did likewise, beating Andrea Petkovic for the loss of just six games.
They now face off for a place in the fourth round, likely to be against reigning French Open champion Barbora Krejcikova, who also enjoyed an easy day in the office when she defeated Christina McHale in straight sets.
Azarenka and Muguruza are tied at 2-all in their overall head-to-head, with a victory each on both hard and clay courts. Both have spent time as world number one, and while both have won two major titles each, neither have saluted since 2013 or 2017 respectively.
It is over eight-and-a-half years since Azarenka won the second of her two Australian Open titles and since then she has struggled with injury and inconsistency, while she has also had to tackle motherhood after giving birth to a son in December 2016.
She did, however, reach last year’s US Open final – her first in seven years – and was in a strong position against Naomi Osaka before having to settle for second-best for a third time.
Muguruza has also struggled for consistency since winning her second major title at Wimbledon in 2017, but over the past 18 months has rediscovered the form that also won her a French Open title in 2016, reaching the Australian Open final (losing to Sofia Kenin) and re-entering the top ten.
Thus, whichever of these players win, in which case they’ll also break a 2-all deadlock in the head-to-head, will have the potential to go deeper in this tournament.
Women’s defending champion Osaka did not have to sweat to reach the third round, receiving a free pass when her Serbian opponent Olga Danilovic withdrew due to a viral illness not believed to be related to COVID-19.
This saw Simona Halep’s second-round match against Kristina Kucova moved to Arthur Ashe Stadium, and the Romanian took advantage of her promotion to Centre Court with both hands, winning in straight sets to advance to the third round for the first time since 2016.
Second seed Aryna Sabalenka also advanced to the third round with minimal fuss, dismissing Tamara Zidansek for the loss of just four games, while Daria Kasatkina came from a set down to oust Olympic Silver Medallist Marketa Vondrousova.
In the early evening match that took place on Arthur Ashe Stadium, Sloane Stephens dismissed another American, 21st seed Coco Gauff, to line up a likely third round clash with 2016 champion Angelique Kerber, who was due to play Anhelina Kalinina in her second round match.
On the men’s side of things, Australian Alexei Popyrin claimed another career scalp when his opponent, 15th seed Grigor Dimitrov, retired in the third set.
The 22-year-old stretched the 2019 semi-finalist to his limits, taking the first two sets in tiebreaks, both decided by 7-4, and was leading 4-0 in the third when Dimitrov was forced to pull the pin due to a foot injury.
He now faces British 24th seed Dan Evans in the third round, with the reward for the victor a possible fourth round showdown with world No.2 Daniil Medvedev, who enjoyed another straight-sets win against German Dominik Koepfer.
Eighteen-year-old Spanish sensation Carlos Alcaraz also advanced to the third round, defeating Frenchman Arthur Rinderknech in four sets to become the youngest man to reach consecutive Major third rounds since Novak Djokovic in 2005. He will next face Stefanos Tsitsipas.
Fifth seed Andrey Rublev also needed four sets to defeat Pedro Martinez, but 16th-seeded Chilean Cristian Garin crashed out at the hands of Swiss qualifier Henri Laaksonen, after winning the first set.
The second round concludes this morning with the top halves in both the men’s and women’s draws in action.
Top seed Ashleigh Barty will get an early start on Arthur Ashe Stadium with her clash against Clara Tauson to start at 12:00pm local time; that is followed by Alexander Zverev taking on Spaniard Albert Ramos-Vinolas.
Men’s world No.1 Novak Djokovic and Wimbledon runner-up Karolina Pliskova co-headline the evening session, with the former taking on Tallon Griekspoor and the latter facing recently-turned 20-year-old American Amanda Anisimova.
Fans with access to Louis Armstrong Stadium will be treated to an enticing triple-header that features Olympic gold medallist Belinda Bencic, two-time Wimbledon champion Petra Kvitova and recently-turned 35-year-old French showman Gael Monfils.
The evening session sees a Canadian double-header with 2019 champion Bianca Andreescu, who is defending maximum points from that result, taking on Lauren Davis before Denis Shapovalov tackles Roberto Carballes Baena in the later match.
The other Australian woman that is still alive in the draw, Ajla Tomljanovic, faces 30th seed Petra Martic on Court 5.
Arthur Ashe Stadium
Day session – play starts at 12:00pm (2:00am AEST)
 Ashleigh Barty (AUS) vs Clara Tauson (DEN)
 Alexander Zverev (GER) vs Albert Ramos-Vinolas (ESP)
Night session – play starts at 7:00pm (9:00am AEST)
 Novak Djokovic (SRB) vs Tallon Griekspoor (NED)
 Karolina Pliskova (CZE) vs Amanda Anisimova (USA)
Louis Armstrong Stadium
Day session – play starts at 11:00am (1:00am AEST)
 Belinda Bencic (SUI) vs Martina Trevisan (ITA)
 Petra Kvitova (CZE) vs Kristyna Pliskova (CZE)
 Gael Monfils (FRA) vs Steve Johnson (USA)
Night session – play starts at 7:00pm (9:00am AEST)
Lauren Davis (USA) vs  Bianca Andreescu (CAN)
Roberto Carballes Baena (ESP) vs  Denis Shapovalov (CAN)
Play starts at 11:00am (1:00am AEST)
Katerina Siniakova (CZE) vs  Maria Sakkari (GRE)
Corentin Moutet (FRA) vs  Matteo Berrettini (ITA)
Shelby Rogers (USA) vs Sorana Cirstea (ROU)
Not before 5:00pm (7:00am AEST)
Jenson Brooksby (USA) vs Taylor Fritz (USA)
For the full Day 4 schedule, please check the US Open website.