Naomi Osaka defeated Wang Xinhu 6-3, 6-3 at Germany's Bad Homburg Open on Friday to reach a first career grass court final.
The four-time grand slam champion and former world number one claimed victory in sweltering conditions in 70 minutes when her Chinese opponent double faulted.
Japan's Osaka has not won a title in more than five years since the 2021 Australian Open. Bad Homburg is her fourth tour-level final since then.
In Saturday's final, sixth seed Osaka faces Czech fourth seed Karolina Muchová, who beat Belgium's Elena-Gabriela Ruse 6-4, 6-4.
The second semi-final had to be suspended midway through because of the heat reaching dangerous levels in central Germany, prompting player welfare protocols to kick in. They returned to finish the contest in the early evening.
Temperatures were in the high 30 degrees Celsius. With possibly even higher temperatures scheduled for Saturday, organizers have decided to start the final two-and-a-half hours early.
The final will start at 11 am (0900 GMT) instead of 1.30 pm.
"This schedule adjustment has been made in response to exceptional weather conditions beyond the tournament's reasonable control and reflects our commitment to prioritizing the health, safety and wellbeing of everyone attending the event," a statement said.
Bad Homburg is an important tune-up for the Wimbledon grand slam which starts on Monday and where Osaka has never gone beyond the third round.
