Zheng, a wildcard entry in Beijing, finally notched her first straight-sets win of this year's tournament having needed more than 10 hours on court to get to the quarter-final.

The world number 54 sent the crowd roaring as she punched winners down the line, though the seventh-ranked Svitolina came back fighting to force a second set tie-break.

Zheng double-faulted on the first point but crawled her way out from a 0-2 deficit and fell on her back victorious after winning her second match point.

"Truthfully, because I really wanted to grab this win, I was really nervous," the 24-year-old told the crowd.

"I played really aggressive in important moments," she said, adding that her opponent "raised her level" in a tight second set.

Svitolina made just 13 unforced errors over the one-hour-and-47-minute match, but was outgunned by 48 winners from the 2024 Olympic champion.

Later on Friday, Poland's Iga Swiatek, the 2023 title winner in Beijing, was due to play Belgium's Elise Mertens for the last semi-final spot.