Nadal powers past Kachenov to set up Isner clash

Top seed Rafael Nadal swept into the quarter-final of the China Open on Thursday with a straight sets victory over the fast rising Russian Karen Kachenov. 

Top seed Rafael Nadal is competing in his first ATP tournament since claiming the US Open in September. Reuters/Jason Lee

Nadal seized control of the encounter by breaking his 21-year-old opponent in the fourth game of the first set before taking it 6-3. He pocketed the second by the same score.

It was a comfortable contrast for the 31-year-old Spaniard who had to fend off two match points during his opening match against Lucas Pouille.

On Friday Nadal will play the sixth seed John Isner. The 32-year-old American was equally impressive in his 6-0 6-3 dismissal of the Argentine Leonardo Mayer.

Isner and Nadal have met six times on the ATP circuit with the Spaniard winning each of their clashes. Eleven days ago, Isner, playing for Team World beat Nadal - representing Team Europe - during the inaugural edition of the Laver Cup;

"Everybody knows that John serves huge and it is so difficult to break him," said Nadal. "And if you add that he is playing very well now from the baseline, he is one of the toughest opponents you can meet."

In the women's draw, fourth seed Karolina Pliskova became the latest high-profile casualty on Beijing's outdoor hard courts. She lost to the unseeded Romania Sorana Cirstea in straight sets .

Cirstea, ranked 44 in the world, blitzed the Czech in the first set winning it 6-1. The second set was tighter but Cirstea held her nerve to edge it 7-5. She will take on the swasbuckling Latvian Jelena Ostapenko. The French Open champion advanced to the last eight when China's top player Peng Shuai retired with a knee injury at 3-0 down in the first set.

Peng, 31, said she had been having injections to ease the pain. "The doctor suggested I should take a period of rest and get it treated," she said. "But I can only rest after the season, that's the plan."