A TIDAL wave of momentum is swelling behind former number one Naomi Osaka as her return to the WTA Tour continues to build steam. For just the third time in her illustrious career – which included four Grand Slam titles – Osaka has won three straight matches on clay, a surface that has always troubled her.

The most recent win was an impressive third round victory over Russian Daria Kasatkina in Rome, getting up 6-3 6-3. It has led to the former number one getting dubbed the nickname ‘Clayomi’, even though the humble Japanese star is trying to keep a lid on it.

“Please don’t,” Osaka said post-match. “Please. I think I need more clay credentials for that. But I’m happy that they’re happy.”

Though clay might have been her nemesis in the past, Osaka is playing the best tennis since returning to tour earlier this year from giving birth to her first child, Shai. She has beaten two Top 20 seeds back-to-back in straight sets, with wins over Kasatkina and previously Marta Kostyuk.

Kasatkina is no slouch on clay either. The Russian 10th seed reached the finals in Charleston on the green clay and has made the fourth round of Rome six times. But in Osaka’s own words, despite copping a hiding in a recent Miami practice match, she “apparently figured out” how to beat the Russian.

Osaka served five aces and won an impressive 64 and 55 per cent of her first and second serve points, while breaking the Russian five times to two in the match. She also hit 30 winners to 25 unforced errors in her best win since returning yet. Osaka said getting in the right headspace and taking her time rather than blazing away with her shots was key.

“It’s definitely more mental,” Osaka said. “I could always do it. I’m a little impatient. Obviously when you hit a heavier ball, for me, I feel like I think about a moon ball. It didn’t really click until I was watching Nadal play and seeing how he actually accelerates so much when he’s doing that, knowing that a heavier ball sometimes is more difficult than a flatter shot.

“Yeah, I feel like I just did a lot of homework.”

At 26 years of age, Osaka continues to learn, and now the Japanese former number one is into the Round of 16 at a WTA 1000 event, the first time since returning to Tour. She will take on Chinese seventh seed Qinwen Zheng in the fourth round for a spot in the last eight.

Zheng defeated Czech teenager Linda Noskova in three sets, coming from behind to post a 3-6 6-1 6-2 victory in one hour and 48 minutes. The winner of Osaka and Zheng will ace either American star Coco Gauff – who was bagelled in the second set but still defeated Jaqueline Cristian in a momentum-swinging match 6-1 0-6 6-3 – or Paula Badosa – who continued her return to form with a come-from-behind win against Russian Diana Shnaider – in the quarter finals.

In the other results, top seed Iga Swiatek won the last five games of the match to get out of jail in the second set against Yulia Putintseva thanks to a 6-3 6-4 win, with American Madison Keys, Romanian Sorana Cirstea and German Angelique Kerber the other winners on the day.