BEIJING, China (AFP) — Olympic champion Zheng Qinwen hailed the atmosphere as “insane” as she thrilled a packed house at the China Open on Saturday to join top seed Aryna Sabalenka in the third round in Beijing.

Zheng, playing at home for the first time since winning Paris gold, swatted aside 71st-ranked Russian Kamilla Rakhimova 6-1, 6-1 in 75 minutes.

Sabalenka in contrast laboured in the first set before defeating tricky Thai qualifier Mananchaya Sawangkaew 6-4, 6-1 in her first match since winning the US Open.

Sabalenka and Zheng are on course to meet in the semi-finals in a repeat of the Australian Open final, where the Belarusian crushed her Chinese opponent 6-3, 6-2, before beating her convincingly again in the US Open quarter-finals.

But with the crowd screaming her on, the 21-year-old Zheng should be a different proposition in the Chinese capital.

The fifth seed plays Nadia Podoroska of Argentina or Ukraine’s 25th seed Dayana Yastremska next.

“The atmosphere was insane. I never thought it would be so full in the center court,” said Zheng, whose victory march was momentarily held up by rain.

“When I was on court today I saw that there wasn’t any empty seats. I was a little bit shocked.”

“I haven’t seen this kind of thing for a while.”

The world number two Sabalenka made hard work in the first set of an opponent ranked 187 in the world and playing the biggest match of her young career.

Sabalenka barely raised a smile at the end after eventually easing to a straight-sets victory.

“I’m super-happy to get through this match,” the 26-year-old said.

“In the first set I was struggling a little bit with the rhythm, with the speed of the court, with the way balls are getting heavier.”

“In the second set seems like everything started working much better.”

The 22-year-old Mananchaya may have been inexperienced at this level but the athletic Thai refused to give up seemingly lost causes.