Iga Swiatek has called for an end to online abuse after receiving hateful messages following her win over Zheng Qinwen at the Cincinnati Open.
World number one Swiatek won 3-6 6-1 6-1 but received criticism after dropping the first set in the last-16 encounter.
The 22-year-old Pole appeared upset in her post-match news conference as she addressed the abuse.
“The amount of hate and criticism me and my team get after losing a set is ridiculous,” said Swiatek.
“I want to encourage people to be more thoughtful when they comment on the internet.
“We all sacrifice a lot. We’re all working really hard to be in that place. We’re always giving 100% of what we can do every day.
“It’s sad for me to see that people I work with, and myself, we’re really judged.”
World number five Ons Jabeur, who reached the quarter-finals after opponent Donna Vekic retired because of illness at 5-2 down in the first set, said much of the abuse aimed at tennis players stems from people betting on the sport.
“Honestly, you win, you lose, you get hate messages no matter what you do,” Jabeur said.
“We need more humanity, more nice people on this earth but I don’t think you can change the mentality of some betters.
“They have nothing to do in their life and they’re spending money on you and probably, what, they lost a couple of bucks on Iga losing a set.”
US Open champion Switek, who is the top seed, will face Wimbledon champion and 10th seed Marketa Vondrousova in the quarter-finals after her win over China’s Zheng.
Zheng took a surprise 3-0 lead in windy conditions but was broken in the fourth game to hand Swiatek a lifeline.
The 20-year-old held her nerve, however, to break the four-time Grand Slam winner again and claim the first set.
But Swiatek regained her composure quickly – swapping her white outfit for a black one – and breezed through the second two sets in rapid time.
Swiatek said her coach suggested the outfit change a couple of months ago as a way to “reset” and go into the second set “with a different vibe”.
She added: “I thought this was a bad [idea] but I tried this time and it worked, so thank you coach.”
Czech Vondrousova, 24, beat American Sloane Stephens 7-5 6-3 in their last-16 tie.
Meanwhile, American world number three Jessica Pegula, who won the Canadian Open title last week, is out after losing 4-6 0-6 to the Czech Republic’s Marie Bouzkova.
Earlier, world number four Elena Rybakina – the 2022 Wimbledon champion – retired when leading 6-4 2-5 in her match against Jasmine Paolini, sending the Italian qualifier into the final eight.
American seventh seed Coco Gauff beat Linda Noskova of the Czech Republic 6-4 6-0, Greece’s Maria Sakkari advanced with a 3-6 6-2 6-3 win over Czech Karolina Muchova andBelarus’ second seed Aryna Sabalenka defeated Russian Daria Kasatkina 6-3 6-3.
