Elina Svitolina said she "was on a mission" for Ukraine after earning a straight-sets win over Russian opponent Anastasia Potapova in the opening round of the Monterrey Open.

The top seed donned the yellow and blue colours of her homeland for Tuesday's match and eased to a 6-2 6-1 victory in a little over an hour in Mexico.

Svitolina only agreed to play her opener after tennis authorities announced a ban on Russian and Belarussian players competing under the name and flags of their countries.

And as Russia's invasion of Ukraine entered its sixth day, the 27-year-old produced an impressive performance that saw her win 73.5 per cent of her first-serve points.

Former world number three Svitolina, who will now face Bulgarian qualifier Viktoriya Tomova, had previously announced she will donate her prize money to the Ukrainian army.

"It's a special one because of what we are going through right now in Ukraine, it's terrifying," Svitolina told reporters. 

"It's been six days and all the Ukrainian tennis players and Ukrainians who are there, we have been really terrified with what is happening.

"For me, playing the match here, I'm not playing only for myself. I'm playing for my country, I'm playing for the help of the Ukrainian army and people in need. 

"I was focused. I was on a mission for my country. From the beginning, it was important to be ready for anything that comes my way."

Petra Martic is also through to round two after recovering from behind to beat third seed Madison Keys 4-6 7-6 (7-3) 6-3.

Marie Bouzkova awaits following the world number 81's 4-6 6-2 6-4 win against Sara Errani. Number eight seed Ann Li's participation in the tournament came to an end with a 6-2 6-1 loss to Wang Xinyu, who will now face Brazil's Beatriz Haddad Maia.

Coco Gauff continued her fine form with a 6-3 6-3 quarter-final triumph over fellow American Amanda Anisimova at the Emilia-Romagna Open.

In a contest between two teenage stars, it was 17-year-old Gauff who sealed her second semi-final spot in as many weeks, having made the last four at the Internazionali d'Italia.

Third seed Gauff will face Katerina Siniakova next, after the Czech followed up her win over Serena Williams with a 7-5 6-1 defeat of Caroline Garcia.

"I was pretty satisfied with the way I played," Gauff said, after fending off Anisimova.

"I do think I could have served a little bit better, but other than that, I was pretty happy with the way I played."

Despite her valid concerns, Gauff won 72 per cent of points after landing her first serve and forced six breaks to win in style, reeling off six games on the trot from 3-0 behind in the second set.

The other semi-final will see second seed Wang Qiang take on Sloane Stephens.

Wang prevailed 7-6 (7-4) 3-6 7-5 against Petra Martic, while Stephens saw off Sara Errani 6-3 6-0.

It was another rain-affected day at the Serbia Open, where Maria Camila Osorio Serrano managed to get past Kamilla Rakhimova 4-6 6-3 6-4.

Anna Kalinskaya and Reka Luca Jani were locked at one set apiece in the only other match to get started before the weather halted play.

Seeds Petra Martic and Coco Gauff were victorious at the Emilia-Romagna Open on Wednesday, but injury cut short Sara Sorribes Tormo's run in the tournament.

Gauff recorded five breaks of serve as she overcame Italian Camila Giorgi in routine fashion, a 6-2 6-3 triumph securing the third seed a place in the quarter-finals.

The American did have a few issues on her own serve, leading to seven double faults, but ended up winning in one hour and 11 minutes.

Martic, the second seed at the event, was made to work in the first set of her match against Ludmilla Samsonova, both players saving a break point on serve as it went the distance.

There was little to split the pair in the tie-breaker too, Martic edging it 7-5 as she capitalised on her first opportunity to take the set.

The second was more straightforward for the Croatian, an early beak of serve putting her in front before she repeated the trick to wrap up victory in the ninth game.

There were wins in straight sets for fellow seeds Caroline Garcia and Wang Qiang too, as they defeated Anna-Lena Friedsam and Martina Di Giuseppe respectively.

For Garcia, the triumph means a first quarter-final appearance in the 2021 season.

Sorribes Tormo was the only seeded player to exit in the day’s action, the Spaniard forced to retire at 2-2 in the deciding set against Sara Errani due to a problem with her left thigh.

"I'm very sorry for Sara. It was a battle, I know every time we play together it is like this. I was mentally ready to fight, to suffer," Errani said in her on-court interview.

Top seed Serena Williams is already out, beaten in straight sets by Katerina Siniakova to deal the 23-time grand slam champion a further blow ahead of this year's French Open.

© 2023 SportsMaxTV All Rights Reserved.