Cincinnati, United States, 15 August 2019 | AAP / AP

Ash Barty dominated Maria Sharapova 6-4 6-1 at the Cincinnati Open to reach the third round of the WTA/ATP hard court event.

She joined fellow Australian Alex de Minaur in the last 16, after the Sydneysider beat Reilly Opelka for the third time in three meetings in 2019.

Countryman Nick Kyrgios on Wednesday night went down 6-7(3) 7-6(4) 6-2 No.8 seed Karen Khachanov.

The top-seeded Barty comfortably beat the former Cincinnati champion in one hour and 27 minutes in the second round on Wednesday to set up a meeting with Estonian Anett Kontaveit, who beat Poland’s Iga Swiatek.

Barty was broken in the third game and trailed 1-3 before reeling off five of the next six games to take the opening set.

The French Open champion then raced to a 3-0 lead in the second before Sharapova pulled one back. But Barty moved ahead 4-1 after the Russian overhit her return of the Australian’s second serve.

The world No.2 broke again with a well-timed drop shot bringing Sharapova to the net, before Barty exquisitely lobbed the Russian to make it 5-1.

The victory meant Barty — who had a bye in the first round — avoided a consecutive opening defeat at a WTA event after she was beaten 6-7(5) 6-3 6-4 by American Sofia Kenin at last week’s Canadian Open in Toronto.

The win is the Australian’s 40th of the season, with her win-loss record of 40-7 leaving her second only to Dutch ace Kiki Bertens (41-16).

It was also Barty’s second victory over Sharapova this year after her fourth-round win in the Australian Open in January.

De Minaur advances

Meanwhile, De Minaur’s victory over Opelka set up a match with in-form Yoshihito Nishioka.

De Minaur, the world No.38, beat the American wildcard in just one hour and 34 minutes on Wednesday to make the third round of an ATP Masters tournament for the second time, after reaching the same stage at Shanghai in 2018.

The Australian also beat Opelka in matches in Sydney and Atlanta earlier this season, both tournaments which he went on to win.

Nishioka stunned compatriot and close friend Kei Nishikori 7-6(2) 6-4 in baseline dual that lasted one hour and 40 minutes.

Nishikori became the seventh seeded man to lose or withdraw during the first two rounds.

“It was a tough match for me,” the Japanese star said afterwards. “I think he played good tennis. Served well … good to see he’s getting stronger, growing up.”

Nishioka’s win comes just after his 7-5 5-7 6-4 win over Australian Jordan Thompson in the second round, meaning the in-form world No.77 may prove a tough opponent for De Minaur.