Defending champion Coco Gauff breezed into the third round of the US Open after a straight-sets win over veteran Tatjana Maria.

The 2023 champion, who said on Monday she will one day win a second title at Flushing Meadows is looking a good bet to do it this year after winning 6-4 6-0.

Her victory included an outrageous shot at the end of the first set where a volley spun so viciously it hit the umpire’s chair and denied Maria what would have been a clear winner.

Gauff said of her win: “I played well overall, I could serve better, I think it could have made the first set a lot easier.

“I am not feeling pressure, I have nothing to lose, I am 20 years old, I already have one grand slam under the belt, whether or not it’s this year, I have the potential to do more.”

Victoria Azarenka battled through a migraine to see off Frenchwoman Clara Burel.

The 20th seed, three-time runner-up at Flushing Meadows looked to be in trouble when she had to have a medical timeout midway through the second set.

She had won the first set but was trailing 3-1 in the second when she began rubbing her temples and eyes.

The Belarussian told the doctor she was seeing spots in her eyes and later confirmed she was suffering from a migraine.

But the medical timeout seemed to affect Burel more than Azarenka as the Frenchwoman’s game crumbled.

Azarenka claimed the 6-1 6-4 victory before breaking down in tears.

“It is very tough to be out here, I don’t know how I played the match, I just hoped it would get better,” she said.

“I have a chronic migraine and it couldn’t be a worse time to start it, it’s tough to deal with.”

Heat exhaustion ruined Iva Jokic’s teenage dream of a third-round meeting with Aryna Sabalenka.

American Jokic, who is 16 and the youngest player in the main draw, was a set up against 29th seed Ekaterina Alexandrova.

But in sweltering conditions, where the mercury was nearly at 40C, the heat got the better of her midway through the second set.

She needed medical treatment and had her blood pressure and pulse checked.

Jokic, a semi-finalist in the Wimbledon juniors last month, rejoined the match but Alexandrova eventually claimed a 4-6 6-4 7-5 victory.

Sabalenka is waiting in the third round after last year’s finalist coasted past Lucia Bronzetti 6-3 6-1.

There was a nice moment as she met with a young fan dressed like her, including a replica tiger tattoo after the match.

The Belarussian said: “It was really adorable moment. I just looked up, and I saw on the big screen a mini-me. It was so cute.

“It’s such a motivation to keep going to inspire the young generation. That’s the main goal.”

The openness and fragility of the women’s top seeds were again highlighted as Wimbledon champion Barbora Krejcikova was ousted in the second round.

The Czech, who beat Jasmine Paolini in the final at SW19 last month, crashed out to world number 61 Elena-Gabriela Ruse.

Olympic champion Zheng Qinwen came from a set down to beat Erika Andreeva 6-7 (3) 6-1 6-2.