Angelique Kerber missed the opportunity to regain the world number one ranking with defeat by Elina Svitolina in the semi-finals of the Dubai Championships.
In wet conditions, Ukrainian Svitolina, 23, earned a third successive win over top seed Kerber 6-3 7-6 (7-3).
The German world number two, 29, would have overtaken Serena Williams if she had taken the title in Dubai.
Svitolina will now face Caroline Wozniacki in Saturday's final after the Dane beat Anastasija Sevastova 6-3 6-4.
Kerber became the oldest player to achieve the number one ranking for the first time in September 2016 and spent 20 weeks at the top.
Wozniacki will contest her second successive final having lost to Karolina Pliskova in Doha.