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.