Angelique Kerber hammered out a 6-3, 6-2 defeat of Ana Konjuh on Thursday to stay in contention for a return to the top WTA ranking at the Dubai Tennis Championships.
Germany's double Grand Slam winner from 2016 can take back the top spot from Serena Williams through a title at the Aviation club on Saturday.
The 29-year-old will first have to get by Elina Svitolina, on course for her own breakthrough into a first-time top 10 ranking if she can win the event.
The Ukrainian reached the final four with a 6-0, 6-4 defeat of Lauren Davis.
Kerber has used Dubai as a building block to repair her modest early season form.
"I'm really happy about the match today again. Ana is a tough opponent, she's going for it. You have to play until the last point. It was nice to get through in two sets.
"I was just focusing on myself and trying to take the rhythm from the last days.
"The match with Svitolina will be another tough one. I have to be aggressive and just like the last days here. I'll just try to enjoy the next match and of course I will try to go out there and to win another match here."
Svitolina, seeded seventh and winner of a fifth career title this month in Taipei, was pleased to advance.
"I'm really happy the way I started and the way I finished the match, I was being very aggressive and it worked really good," said Svitolina.
"I was calm and positive today. I'm really happy with the performance.
"I was expecting she would do something different after losing 0-6 - it's always tough. I was expecting her to come back to the game.
"I was trying to stick to my plan and stay really positive. I knew that there would be some up-and-downs, but I tried to do more, more effort from my side so I didn't lose my focus too much."
Tenth seed Caroline Wozniacki produced an identical scoreline to Kerber as she put out teenaged Californian Catherine Bellis 6-3, 6-2 to end the 17-year-old's run of form which had produced a third-round upset of fourth seed Agnieszka Radwanska.
Latvian Anastasija Sevastova ended the week's last Chinese hope, defeating Wang Qiang 6-4, 7-5 as the Asian lost her first sets of the week.