Top seed Dominic Thiem was knocked out the Rio Open in the first round on Tuesday, going down 6-3, 6-3 to Laslo Djere.
Swiss seventh seed Belinda Bencic was stunned by Slovakia's Magdalena Rybarikova while former champion Ana Ivanovic was also sent packing in third-round action at the BNP Paribas Open in California.
Croatian ninth seed Marin Cilic reached the Wimbledon quarter-finals for the third year running after Kei Nishikori quit with a rib injury midway through their fourth round match on Monday.
Summary of sports events and persons who made news on Tuesday
A summary of Day 2 at Wimbledon on Tuesday.
Romania's Simona Halep kicked off her campaign for a maiden WTA Finals title in emphatic fashion with a thumping 6-0, 6-3 victory over US Open champion Flavia Pennetta in the opening match of the eight-woman season-ending tournament on Sunday.
As Serena Williams sits out a fourth straight Grand Slam, Simona Halep and Karolina Pliskova will join Caroline Wozniacki in a quest for a major breakthrough in Australia.
Eugenie Bouchard pulled off her first win over Maria Sharapova with a 7-5, 2-6, 6-4 triumph in the Madrid Open on Monday in a thrilling contest full of tension after the Canadian had called the Russian a cheater following her doping ban.
Claycourt master Rafael Nadal quickly adapted to his new surroundings at Roland Garros with a 6-2, 6-1, 6-3 demolition of German qualifier Yannick Hanfmann in the first round of the French Open on Monday.
Twelfth seed Djokovic resumed two sets to one ahead after snatching a third-set tiebreak the previous night before Wimbledon's 11pm curfew left the match on a knife edge.
It would be perfectly safe for Serena Williams to continue with rigorous training throughout pregnancy, but how quickly the 35-year-old would return to tournament tennis is uncertain.
With Serena Williams vying to safeguard her World No 1 ranking and Djokovic fighting off a wrist injury, expect to see a few surprises at the fourth and final Grand Slam of the year
Eleven-times champion Rafael Nadal booked his place in the semi-finals of the Barcelona Open semi-finals by beating German Jan-Lennard Struff 7-5, 7-5 in a hard-fought match on Friday.
World number one Simona Halep swatted aside American Nicole Gibbs while Maria Sharapova was flawless in her straight sets victory over Romania's Mihaela Buzarnescu in the opening round of the Shenzhen Open on Monday.
A long measure of Grand Slam patience paid off for Peng Shuai of China, who reached the semi-finals of the US Open on Tuesday by routing Swiss teenager Belinda Bencic 6-2, 6-1 in the Flushing Meadows heat.
Caroline Wozniacki upset French Open champion Maria Sharapova in a groundstroke marathon to reach the U.S. Open quarter-finals, while Gilles Simon registered the first big surprise in the men's draw.
amiliar names, however, are tipped to take off with the winners' trophies. The following is a list of talking points at the Australian Open:
For the second straight year Serena Williams saw her bid for a seventh U.S. Open title halted in the semi-finals with a 6-2 7-6(5) loss to Karolina Pliskova on Thursday that also ended her long reign as world number one.
Form guide for American Serena Williams ahead of Thursday's US Open semi-final clash against Latvia's Anastasija Sevastova:
Rafael Nadal gave a much improved performance to advance into the quarter-finals of the Barcelona Open on Thursday, dispatching Spanish compatriot and crowd favourite David Ferrer 6-3, 6-3.
IMAGES of the all the action from Day 2 of the Australian Open played at Melbourne Park on Tuesday
Rafael Nadal rallied from a set down to ease past Fabio Fognini 4-6, 6-1, 6-2 in the Italian Open quarter-finals on Friday and set up a mouth-watering clash against long-time adversary Novak Djokovic for a place in Sunday's final. Djokovic plotted a similar path to the Spanish clay-court king when the Serb lost the first set against Japan's Kei Nishikori before recovering to win 2-6, 6-1, 6-3 and seal an open-era record 51st career meeting against Nadal.
Serena Williams beat her sister Venus 6-4, 6-4 in the Australian Open final on Saturday to win her 23rd grand slam singles title and become the most successful tennis player in the open era.
It was a day of surprises at Flushing Meadows in New York as seeded players were knocked out one after the other on Friday.
Factbox on American Serena Williams, who plays sister Venus in the final of the Australian Open on Saturday.
A summary of sports events and sports persons, who made news on Friday.
Afghanistan registered a thumping 202 runs victory over New Zealand to move into the Super League semi-finals of the ICC U19 Cricket World Cup in Christchurch on Thursday.
Roger Federer is keeping a lid on expectations.
On the men's side, the fields have already been divided into two ATP 250 tournaments.
Russian sixth seed Anastasia Pavlyuchenkova claimed her third title of the year by beating seventh-seeded Australian Daria Gavrilova in the final of the Hong Kong Tennis Open on Sunday.
Defending champion Serena Williams is the top seed in the women's draw. The American will be looking to equal Steffi Graf's Open era record by sealing a 22nd Grand Slam triumph.
Images from Day 1 of the US Open in New York, on Monday.
IMAGES from Day 2 of the US Open played at Flushing Meadows in New York on Tuesday.
Rafael Nadal swept into the quarter-finals of the Italian Open on Thursday with a ruthless 6-4, 6-1 victory over Canadian teenager Denis Shapovalov. The top seed, who will reclaim the world number one ranking from Roger Federer if he wins his eighth title in Rome, turned in a near-flawless performance, losing only five service points as he honed in on victory in an hour and 22 minutes.
It was Novak Djokovic's first match this year after his Australian Open hopes were dashed when he was deported following an 11-day saga revolving around his decision not to have a COVID-19 vaccination.
Big-serving Canadian Milos Raonic made a strong return to competition on Friday by beating Viktor Troicki 6-3, 7-5 to reach the third round of the Miami Open.
Nadal, who got a first-round bye, defeated Richard Gasquet 6-3, 6-4 to advance.
ATP says 'no evidence' against Harrison's racist remarks
Roger Federer and Maria Sharapova glittered under the Rod Laver Arena lights on Monday, restoring order at the Australian Open after eight women's seeds crashed out in the afternoon sun on a manic opening day. The evergreen Federer strolled into the second round with a classy 6-4, 6-2, 7-5 win over Taiwan's Lu Yen-Hsun before fellow-second seed Sharapova ruined Croatian qualifier Petra Martic's 24th birthday with a 6-4, 6-1 victory.
The match ended in 52 minutes as Williams played her forehand into the net.