If Arina Rodionova's Thailand Open doubles campaign alongside Yue Yuan falters through fatigue, the pair will only have themselves to blame.
In Tuesday's singles first round they faced each other, and slogged it out for nearly three hours in steaming conditions in Hua Hin.
Australian No.1 Rodionova, seeking to break into the world's top 100 for the first time, eventually prevailed against her sixth-seeded opponent 7-6 (8-6) 4-6 6-3.
"It was crazy. It was so hot and humid. We played for nearly three hours and she hits the ball so hard,” said Rodionova, who now plays another Chinese, Zhuoxuan Bai, on Thursday.
“I didn't really have much off-season, I just played a lot of matches so that's where I got my fitness from. I took it one point at a time, fighting as hard as I can. That's about it. That's my secret. Experience helps as well."
There was less joy for the other Australian left in the draw, teenager Taylah Preston, who is also defending a new rankings high.
The world No.199 had a tough draw against Lin Zhu, the defending champion, but went down fighting 6-4 7-5.
“It was a really tough match for me. I think she played really well today,” said the No.2 seed of the West Australian.
"I never really saw her play before so it was tough for me to read her game. I was really happy to hang in there and find solutions."
Elsewhere seeds Tatjana Maria and Yulia Putintseva also progressed.
Maria, a former Wimbledon semi-finalist, won 6-3 6-1 against qualifier Arianne Hartono while Thailand’s Thasaporn Naklo took a set from Putintseva despite being ranked 336 places below the Kazakh.
Top seed Magda Linette was knocked out on Monday by Diana Shnaider who faces Paula Badosa on Wednesday.
In the Upper Austria tournament in Linz former world No.1 Angelique Kerber, now aged 36 and still on the comeback trail after 18 months out while she became a mother, lost 6-1 6-3 to Lucia Bronzetti.
