Novak Djokovic is on the verge of completing something truly great.
With Wimbledon, the French and Australian Open already in the bag in 2021, victory in the U.S. Open would see the Serbian tennis superstar become the first man to win a calendar year Grand Slam in 52 years.
You have to go all the way back to Rod Laver in '69 for the last to do it in the men's game and even in the women's game no-one's managed it since Steffi Graff in 1988. The German even claimed a 'Golden Slam' by winning the Olympic gold medal in Seoul too.
At 34, Djokovic can bounce back from Tokyo 2020 disappointment to finally rise above Federer and Nadal on the Grand Slam charts with a record-breaking 21st triumph - all three are currently tied on 20.
Djokovic called it a "very unique opportunity," in his pre-tournament press conference saying the "pressure is a privilege."
"I know how big an opportunity is in front of me here in New York where historically I've played really well over the years. It's probably the most entertaining tennis court that we have, crowd will be back in the stadium, I can't wait.
"Honestly I am very motivated to play my best tennis, I have to hit one ball at a time, just try and be in the moment and have a guiding star in a way.
"It would be a dream to win a Slam here which would obviously complete the calendar Slam, I'm hugely inspired and motivated by that. No doubt."
Djokovic: From Olympic despair to Grand Slam glory?
With no Federer or Nadal in his way, Djokovic is just seven matches from Grand Slam glory, but as Germany's Tokyo 2020 Olympic champion Alexander Zverev proved in the Japanese capital, "Djoker" is human after all.
Serbia's gold medal favourite came into the Tokyo Games in imperious form winning the Australian Open in February, the French Open in May, and then Wimbledon in June.
But Zverev stunned Djokovic in the semi-finals of Tokyo 2020 on 30 July coming back from a set down to win 1-6, 6-3, 6-1.
Djokovic was deeply disappointed as his 'Golden Slam' dream was over.
“I feel so terrible right now, can’t be positive right now,” he said afterwards. “I don’t know I feel terrible… in every sense, but tomorrow hopefully, a fresh start. I can recover and at least win one medal for my country.”
He went home without an Olympic medal and hasn't played competitively since then, opting out of warm-up events ahead of the US Open to work on his game from his home base and arrive in New York fully rested.
Now he's revved up once more and on the record chase.
Novak Djokokic records
Already established as one of the all-time greats, Djokovic could reach another level of greatness with victory at the 2021 US Open in New York.
With 85 career singles titles, including 20 Grand Slams, five year-ending championships and 36 ATP Masters Series 1000 titles, his legacy is secure, but he's far from finished.
There are only two other men besides Djokovic in the men's draw who have won Grand Slam singles titles in New York: Marin Cilic and Andy Murray. Other contenders include Olympic champ Zverev, Daniil Medvedev and Stefanos Tsitsipas.
While the Serbian may not have won the US Open since 2018, he is top seed and clear favourite for most.
Here's a look at some of his incredible achievements so far, and some records he can break in New York.
Three big records Novak Djokovic is chasing at the 2021 US Open
1. Most weeks at No.1
Federer's record of 310 weeks as world number one on the ATP Tour fell to Djokovic back in March when he reached 311, and by the beginning of the US Open on 30 August the Serbian sensation was at 335, more than an other man in the 48-year history of the ATP Rankings.
He has held the top spot in the rankings across five different stints.
Djoko also overtook Martina Navratilova on the all-time standings, who was at the top for exactly 332. But Steffi Graff did it for 377 weeks, and that's the mark to aim at.
By winning the big prize in the Big Apple, Djokovic can take another step closer to Graff.
2. Exceed 20 Grand Slam titles
By winning Roland Garros last June, Djokovic also became the first to win all major tournaments at least twice since Rod Laver and Roy Emerson at the start of the Open era in 1968.
If he wins his 21st slam in the States then that would be a new record and would put him ahead of perennial rivals Federer and Nadal who he's spent a career chasing.
21 would be the most any man has ever won.
And with Serena Williams on 23 and Margaret Court on 24, it's conceivable that Novak could go on to become the most successful tennis player of all time in major tournaments.
3. Successfully complete the calendar Grand Slam
Not since Rod Laver in 1969 has the world of tennis seen a calendar Grand Slam of the Australian and French Opens, Wimbledon and the U.S. Open, now Djokovic is on the verge.
To date his Grand Slam victories are:
2008, 2011, 2012, 2013, 2015, 2016, 2019, 2020, 2021
2011, 2014, 2015, 2018, 2019, 2021
2011, 2015, 2018
Beijing 2008 singles bronze
Novak Djokovic at the 2021 US Open: Schedule
The 2021 US Open runs from 30 August - 12 September.
The men's final is scheduled for Sunday, 12 September.