US Open Day 1: Naomi Osaka wears 'Breonna Taylor' face mask, Coco Gauff defeated in first round

Naomi Osaka continued to keep her social justice message front and centre after the Japanese fourth seed adorned a black face mask with the name 'Breonna Taylor' before and after her first round win in the US Open on Monday night.

Osaka initially withdrew from her semi-final at the Western & Southern Open on Thursday to protest the police shooting of Jacob Blake, a Black man in Kenosha, Wisconsin. She played the rearranged match on Friday but pulled out of the final due to a hamstring injury.

That injury showed few signs of returning but Osaka had to dig deep to beat compatriot Misaki Doi 6-2 5-7 6-2 in her opener at Flushing Meadows.

The past week saw Osaka, 22, emerge as tennis' torchbearer in protests and the face mask in tribute of Breonna Taylor - a Black woman killed by police officers who burst into her apartment in March - was the latest stand by the two-time Grand Slam champion to raise awareness of racial injustice in the United States.

"Actually, so I have seven [masks]," said Osaka. "It's quite sad that seven masks aren't enough for all the names. Hopefully I'll get to the final so you can see all of them."

With no spectators allowed into the Billie Jean King National Tennis Center due to Covid-19 health and safety protocols, large sections of seating in the Arthur Ashe Stadium court were covered with 'Black Lives Matter' banners.

Osaka, the 2018 champion, started strongly in the opening set as she broke Doi's serve twice without facing a single breakpoint.

But she struggled with her serve in the second and her unforced errors mounted as the 81st-ranked Doi, who lost to Osaka in their only previous meeting in 2016, levelled the match with a second break.

Normal service was resumed in the decider, however, as Osaka broke her Fed Cup team mate early before sealing the win with a second break.

"It was very difficult and I kind of expected it because first-round nerves and also she's a tough opponent so I knew there was a chance it would get really long," Osaka said in a courtside interview.

"I felt like it could have been better (with my serve) but it did what it needed to do on the very important points so I can't be that mad. I definitely need to practise some more."

Next up for Osaka will be Italian Camila Giorgi, who earlier beat Alison van Uytvanck 2-6 6-1 7-5.

Gauff 'still has a lot to learn'

Earlier, American teen sensation Coco Gauff was eliminated from the first round of a Grand Slam for the first time.

Gauff, whose run to the third round ignited last year's tournament, bowed out 6-3, 5-7, 6-4 to Anastasija Sevastova at an empty Louis Armstrong Stadium.

Having reached the fourth round at the Australian Open in January and Wimbledon in her Grand Slam main draw debut last year, 16-year-old Gauff had never felt the pain of an early exit from the majors.

"I could have played better today," Gauff told reporters. "I just got on Tour a little over a year ago, so I still have a lot to learn and a long ways to go."

Old guard march on

Top seed Karolina Pliskova overcame an error-strewn first set to defeat Ukraine's Anhelina Kalinina 6-4, 6-0 to reach the second round.

Pliskova, seeded first following the withdrawals of world No 1 Ashleigh Barty and second-ranked Simona Halep, will next face France's Caroline Garcia, who came through her first round match 6-3, 6-2 against Italian Jasmine Paolini.

Angelique Kerber, the 2016 champion, navigated a tricky first round tie, defeating Australia's Ajla Tomljanovic 6-4, 6-4 and will face fellow German Anna-Lena Friedsam in the second round.

Two-time Wimbledon champion Petra Kvitova produced a fine performance on the opening day, defeating Romania's Irina-Camelia Begu 6-3, 6-2. The sixth-seeded Czech will next take on Kateryna Kozlova.