Spanish great Rafael Nadal has been knocked out in the third round at the US Open by Italy's Fabio Fognini.
Nadal won the first two sets but lost the next two, then the fifth set was a topsy-turvy rollercoaster.
Neither player could hold serve for seven straight games in the decider, before Fognini finally broke to love in the ninth game for a 5-4 lead, then served out the match to win 3-6 4-6 6-4 6-3 6-4.
Fognini hit 70 winners to Nadal's 30 to win in three hours and 46 minutes.
The 32nd-seeded Italian - a clay court specialist - goes on to face Feliciano Lopez for a place in the quarter-finals in New York, after the Spaniard upset the 10th seeded Canadian Milos Raonic in straight sets.
The defeat ended eighth-seeded Nadal's streak of 10 years in a row with at least one grand slam singles title after the Spaniard lost in the quarters at the Australian and French Opens, while going down in the second round at Wimbledon.
Serena's calendar slam still on
Serena Williams gave her home fans a big fright before seeing off compatriot Bethanie Mattek-Sands in another evening thriller.
Mattek-Sands easily won the first set 6-3, taking all of her break point opportunities, but Williams came alive after that, the world No.1 winning the second set 7-5 then the decider 6-0 as her younger countrywoman faded badly.
The 34-year-old now faces another American youngster, 20-year-old Madison Keys, for a place in the quarter-finals and another place in tennis history.
Williams, who's won six times in New York, already holds all four major titles but she's seeking a calendar-year slam. And that would put her equal-second in the all-time record books with German great Steffi Graf - if Williams wins in New York she'll equal Graf's mark of 22 career majors.
Australian legend Margaret Court holds the all-time record of 24 slams.
William's older sister and former champion Venus Williams also went through to the last 16, the American recording a straight sets win over Swiss player Belinda Bencic.
Men's world No.1 Novak Djokovic notched another straight sets win, over Italian Andreas Seppi.
Ferrer second-biggest shock on day five
Seventh seed David Ferrer was another big shock to depart on day five, the Spanish veteran and four-time Auckland champion sent packing by 27th-seeded Frenchman Jeremy Chardy.
Ferrer could only hold off the inevitable as the usually industrious 33-year-old won just one set as Chardy triumphed 7-6 4-6 6-3 6-1.
The 10th seed Milos Raonic was also knocked out in the third round, the big-serving Canadian losing in straight sets to Spain's Feliciano Lopez, the 18th seed winning 6-2 7-6 6-3.
Defending champion Croatian Marin Cilic was given a scare before advancing to the fourth round with a five-set win over Kazahkstan's Mikhail Kukushkin.
Cilic dropped the first and fourth sets before easing through the decider, winning 6-7 7-6 6-3 6-7 6-1.
Frenchman Benoit Paire easily eliminated 26th-seeded Spaniard Tommy Robredo, Paire winning 7-6 6-1 6-1.
Another Spain native, 23rd-seeded Roberto Bautista Agut, knocked out 14th-seeded Belgian David Goffin, who retired while trailing in the fourth set.
Also through are 19th-seeded French star Jo-Wilfried Tsonga, 13th-seeded Russian Ekaterina Makarova, and 25th seed Eugenie Bouchard of Canada.
NZ's Daniell, Venus depart in doubles
There are no more New Zealanders alive in the men's doubles after both Davis Cup players Marcus Daniell and Michael Venus were knocked out in the second round.
Daniell and his British partner departed the grand slam after a great start in their match.
The Wairarapa native had teamed up with Jonathan Marray, a Wimbledon winner two years ago, and Daniell, on debut at the US Open, won the first set against Austria's Phillipp Oswald and Canadian Adil Shamasdin.
But ultimately Daniell and Marray fell at the final hurdle, as Oswald and Shamasdin came back to take the match in the third-set tiebreak, winning 4-6 6-4 7-6.
Venus and Croatian partner Mate Pavic also won a set but fell to 12th seeds Pierre-Hugues Herbert and Nicolas Mahut, the French combination winning another tight one in a third-set tiebreak, taking it 6-3 6-7 7-6.
Another New Zealander, Russian-born Artem Sitak, also bowed out in the mixed doubles in the first round on Saturday - though he and Ukrainian partner Elina Svitolina won the first set against controversial Australian Nick Kyrgios and Canada's Bouchard.
But Kyrgios and Bouchard came storming back to win 5-7 6-3 10-3.