US Open champion Naomi Osaka apologised to Zhang Shuai for an emotional display in beating the Chinese in Beijing.

The 20-year-old Japanese was close to tears at points in her 3-6 6-4 7-5 win in the China Open quarter-finals.

Osaka wept in the wake of her US Open win, overshadowed by Serena Williams’ confrontation with umpire Carlos Ramos, and was again facing a crowd favourite.

“I was basically apologising because I feel I was more emotional than I normally try to be,” said Osaka.

Asked the cause of her emotion, she said: “Because it was a hard match. That’s basically why.”

Unseeded Zhang took advantage of a string of early errors to take the first set and was a break up in the second before being reeled in by world number six Osaka, who will play Latvia’s unseeded Anastasija Sevastova in the next round.

• Live scores, schedule and results
• Alerts: Get tennis news sent to your phone