US Open 2019: From Naomi Osaka stunning Serena Willams to John Millman beating Roger Federer, top 10 upsets of 21st century

Nothing makes sport more interesting and fascinating to follow than upsets. To witness an unheralded player come out on top over their senior opponent or the overwhelming favourite. There are always results that make one sit up and notice — an announcement by a young star of what is to come a few years later. Or simply eyebrow-raising results where the favourite just couldn't go over the finishing line. Presenting 10 biggest US Open upsets since 2000:Naomi Osaka beat Serena Williams in 2018It wasn't the first meeting Serena and Naomi for the Japanese player had beaten her in Miami in the same year. But the stage was much bigger and the odds even higher. It was a Grand Slam final and Serena was the queen of title matches. Not only was Osaka not affected by the stage, the opponent, but she also kept her head in the game even as Serena suffered a meltdown. To highlight her dominance, Osaka sealed the title with an ace for her first major.John Millman beat Roger Federer in 2018Australian John Millman was making his first appearance in the second week of a grand slam. And he could not have been handed a tougher draw than Roger Federer on Arthur Ashe Stadium. Everyone expected it to be a walk in the park for Federer but the Aussie had other ideas. Millman came from a set down to beat Federer 3-6, 7-5, 7-6, 7-6 where he saved set points in second and third sets while coming from 2-4 down in the fourth. It did help enormously that Federer made a jaw-dropping 77 unforced errors. Not bad for his first top-10 win.Kaia Kanepi beat Simona Halep in 2018The atmosphere in New York isn't to the liking of Simona Halep. The loud crowd makes things difficult for everyone involved and it played a role in the then World No.1's straight-set defeat to Kaia Kanepi who had come through the qualifiers to reach the quarter-finals a year prior. Even though Halep had had a great season, it just didn't work at Flushing Meadows as she lost 2-6, 4-6 inside the new Louis Armstrong Stadium. She thus earned a sorry milestone of becoming the first top-seeded woman to lose in the first round of the US Open.Naomi Osaka beat Angelique Kerber in 2017[caption id="attachment_7224441" align="alignnone" width="825"] Naomi Osaka announced herself with a big win over Angelique Kerber. AP[/caption]Osaka's first impressions and rise were on the American hardcourts, especially at the US Open. In 2016, she was 5-7, 6-4, 5-1 ahead in the third set over Madison Keys before losing 6-7. A year later, she created the first big impression by sending defending champion Angelique Kerber packing in the first round. If Kerber was not having a great season until then, the early exit just dampened her plans further. Under the roof on Arthur Ashe Stadium, Osaka, then 19, out-played Kerber to win 6-3, 6-1 for her first top-10 win. The German became only the second defending US Open women's champion to lose in the first round after Svetlana Kuznetsova in 2005.Roberta Vinci beat Serena Williams in 2015If Serena's immediate quest now is to level Margaret Court, in 2015, in the last week of August, it was to become the first player since 1988 to complete a 'Career Grand Slam' or win four majors in a calendar year. And it looked like she was on the cusp of it with Halep, Flavia Pennetta and Roberta Vinci left in the draw alongside her in the last-four. Facing Vinci in the semi-final, Serena had no answer to her grit and sliced backhand. From a set down and 0-2 in the third, Vinci came back to set up an all-Italian final.Marin Cilic beat Roger Federer in 2014Coming into their US Open semi-final, Marin Cilic had taken just two sets off Roger Federer in their last five meetings. Federer, seeking a sixth US Open title, had nothing to offer in response to Cilic's big, booming flat serve and equally dominant forehand. The Croat needed to be at the top of his game to beat the Swiss and he did just that, not only then but also in the final against Kei Nishikori to lift the title.Juan Martin Del Potro beat Roger Federer in 2009Possibly the reason why Federer features so frequently in such lists is because he is almost unbeatable on all surfaces except clay. On the hard courts of Flushing Meadows, Federer had won five straight titles coming into the 2009 edition and looked set to make it six. In his path stood tall Argentine Juan Martin Del Potro. In a five-set final, the first to go the distance in US Open history in 10 years, Del Potro won 3-6, 7-6, 4-6, 7-6 and 6-2. Del Potro's win — first by an Argentine man in New York since Guillermo Vilas in 1977 — required 4 hours and 6 minutes and in the end, it seemed all worth it.Julie Coin beat Ana Ivanovic in 2008Ana Ivanovic had triumphed at Roland Garros in 2008 and came into the US Open as the World No 1. She was not particularly considered a favourite but expected to go deep in the draw. That, however, wasn't on the cards thanks to World No 188 qualifier Julie Coin. Her 6-3, 4-6, 6-3 win denied Ivanovic on improving her year after a third-round exit at Wimbledon. It marked the earliest defeat of a women's top seed at the US Open since 1973.Arnaud Clement beat Andre Agassi in 2000Frenchman Arnaud Clement came into the 2000 US Open as the World No 37 and had the difficult task of facing legendary Andre Agassi in the second round itself. All things pointed at a difficult time for Clement who, like Agassi of the past, was more famous for his stylish looks than for his tennis. That changed following Clement's win over the defending champion and World No 1 Agassi. The American was the overwhelming favourite and had the form to back him up as well. In an un-Agassi like showing, the American went down 3-6, 2-6, 4-6.Wayne Arthurs beat Gustavo Kuerten in 2000Gustavo Kuerten made his mark on the clay and that remained his most successful surface during his playing career. He came into the US Open with the title in Paris earlier in the year. In the first round, he was drawn against leftie Wayne Arthurs who was on top of his game at Flushing Meadows. The Aussie served 26 aces and sent in 69 winners to beat the Brazilian 4-6, 6-3, 7-6, 7-6. 'Guga's' defeat marked the second time since 1956 that the No 2 seed lost in the first round.