Alex Eala’s staying power will be put to the test when the world No. 53 plays Petra Marcincko of Croatia in the Round of 16 and in women’s doubles on Thursday in the Auckland Open in New Zealand.

Fresh from her triumphant teamup with world No. 35 Iva Jovic of the United States in doubles where they topped world No. 13 and Elina Svitolina of Ukraine and seven-time Grand Slam champion Venus Williams, 7-6, 6-1, in the Round of 16 last Monday, Eala faces another stern test.

Marcinko, though rated No. 80, earned the right to meet Eala after slipping past world No. 33 Camila Osorio of Colombia, 6-4, 0-6, 7-6.

Still, Eala remains the pre-match favorite given her latest exploits.

Before sparkling in doubles play, Eala scored a 4-6, 6-4, 6-4 victory over former world No. 17 and 2024 Paris Olympics silver medalist Donna Vekic, also from Croatia.

But come Thursday, Eala’s endurance will be tested.

First, Eala will Marcinko at 8 a.m. (Manila time) before joining forces with Jovic in the women’s doubles match against Jesika Malecková of the Czech Republic and Renata Zarazúa of Mexico on the same day.

While she and Eala are at the same age, Markovic will just make her Grand Slam main draw debut at the Australian Open at Melbourne Park on 18 January.

Markovic also boasts a Junior Grand Slam title, an Australian Open title in 2022 where she defeated Sofia Costoulas of Belgium, 7-5, 6-1, in the final.

Meanwhile, Eala will enter her fourth Grand Slam main draw of her career and even won a match, a 6-3, 2-6, 7-6 victory over world No. 14 Clara Tauson of Denmark in the first round of the US Open last August.

She also has three Grand Slam titles, a 2022 US Open girls’ singles title, a 2021 French Open doubles crown with Oksana Selekhmeteva of Russia and a 2020 Australian Open doubles tiara with Priska Nugroho of Indonesia.

Apart from Williams, Eala already has a list of Grand Slam champions she has defeated, including Iga Swiatek of Poland, Jelena Ostapenko of Latvia, and Madison Keys of the United States.

If Eala pulls off another victory, she will take on the winner between world No. 52 Magda Linette of Poland and world No. 81 Elisabetta Cocciaretto of Italy in the quarterfinal.

The Auckland Open is part of Eala’s preparation for the Australian Open, the first Grand Slam of the year.

Meanwhile, Malecková and Zarazúa will be formidable foes after pulling off a 3-6, 6-2, 12-10 win over No. 1 seed Asia Muhammad of the US and home bet Erin Routliffe last Tuesday.