Jabeur, who has endured a stop-start season in which she had minor knee surgery before winning the title in Charleston and skipping the Madrid Open with a calf problem, was slow out of the starting blocks and Danilovic took full advantage of it before experience prevailed.

Danilovic wrapped up the opening set with a winner for a decisive break in the 10th game and was toe to toe with Jabeur until midway through the second.

Jabeur stole the Serbian's serve for 3-2, only for her opponent to rally and level for 4-4. An unforced error, however, allowed the Tunisian to take a 5-4 advantage and she held to take the set to the delight of dozens of Tunisian flag-waving fans.

Jabeur raced to a 4-1 lead in the decider and Danilovic twisted her ankle after having pulled a break back. At change of ends before her opponent served for the set at 5-2 after another break of serve, Danilovic had her ankle strapped by the physiotherapist.

The Tunisian wrapped up the victory on the second match point with a forehand winner, setting up a meeting with American Bernarda Pera.

"I want to congratulate Olga for this great match, she plays so well and thanks to the crowd on a day I didn't play my best tennis," said Jabeur.

"I won it thanks to my mental strength. I accepted that I was not at 100% and that I needed to find solutions with what I had today.

"She made it hard for me today but I managed to scrape a few important points here and there."