The history of the US Open is a rich one, of great champions, great matches, great excitement and, inevitably, great upsets.
The 2023 competition in New York will no doubt provide their fair share of shocks and surprises and, to whet the appetite, here are a selection of memorable upsets from down the years.
|US Open 2023
|Billie Jean King National Tennis Center, Flushing Meadows, New York
|Monday 28th August - Sunday 10th September, 2023
|How to watch
|bet365 Sports Live Streaming and Sky Sports
|Men: Carlos Alcaraz 6/5, Novak Djokovic 6/4, Daniil Medvedev 9/2
Women: Iga Swiatek 9/4, Aryna Sabalenka 5/1, Elena Rybakina 6/1
Andrew Pattison was a little-celebrated, South African-born Rhodesian who had not gone beyond round three at a grand slam when he arrived at the US Open in 1973 - and few expected it to be any different that year.
For standing in Pattison's way in round two was the reigning champion and No.2 seed Ilie Nastase, a man who earlier that summer had won the French Open without dropping a set and also reached the final at Wimbledon.
Pattison, who had lost in the first or second rounds of 20 of the 23 tournaments he had played prior to the US Open, was ranked 79 in the world and no one thought he could give the maverick Romanian a game.
They certainly didn't think that when Nastase breezed through the first two sets.
But Nastase's game waned, Pattison somehow found something, levelled the match in near-darkness and came back the following day to nervelessly finish the job, winning 6-7 2-6 6-3 6-4 6-4.
Seventy-seven places separated Nastase and Pattison in the world rankings, but there was an even bigger gulf ahead of an even bigger upset when Paul Haarhuis stunned John McEnroe in 1989.
McEnroe, past his best admittedly, was still No.4 in the world. Haarhuis was at 115. This had mismatch written all over it.
Haarhuis, who had been ranked 705th a year earlier, had never played a hard-court tournament on the main tour in his career before that US Open and with a nice line in self-deprecation suggested: "I come from Mars."
McEnroe admitted he knew absolutely nothing about his second-round opponent, though he knew the name after Haarhuis had put the tin lid on an astonishing 6-4 4-6 6-3 7-5 victory.
Not that McEnroe sat alone on the naughty step that day, one of the great days in US Open history. Just a few hours later No.5 seed Mats Wilander was also beaten at an unseeded teenager by the name of Pete Sampras. Wonder what became of him?
Shocks didn't come much bigger than when Serena Williams lost her 2015 semi-final to Italy's Roberta Vinci, a 2-6 6-4 6-4 loss that left her inconsolable.
"She played out of her mind," was all that needed to be said by Williams, then the superstar of the women's game and just two matches away from completing the first calendar grand slam in 27 years.
Williams was the defending champion and world No.1. Vinci, a 32-year-old doubles specialist ranked 43 in the world, was playing her first ever major semi-final and given absolutely no chance.
"I didn't expect that, no," confirmed the Italian afterwards, though the fairy tale ended there, as she was beaten by compatriot Flavia Pannetta in the first-ever all-Italian final.
Everyone will have their own idea of the ultimate US Open shock, but surely the day Ana Ivanovic lost out to Julie Coin in 2008 is at the top of most lists.
French Open champion and world No.1 Ivanovic was fancied to make light work of Coin, the world No.188, who was contemplating quitting tennis at the end of the year because her results had been so dismal.
The Frenchwoman had never even reached the main draw of a grand slam singles event and had to go through qualification to make it.
Ivanovic had never seen Coin play and few imagined that would amount to much, except Coin was about to tear up the script, outbattling her illustrious opponent en route to a wonderful 6-3 4-6 6-3 success.
So unexpected was the win that no one in France saw it - their broadcasters were showing the game featuring her compatriot Amelie Mauresmo.
Ivanovic had become the first top-seeded woman in the Open Era to lose before the third round of the US Open. Now that's what you call an upset.