Azerbaijan's world champion Irina Zaretska is set to compete at the Karate 1-Premier League in Istanbul ©Getty Images

Istanbul is set to open the 2021 Karate 1-Premier League season tomorrow, with seven of the incumbent Grand Winners set to compete.

Grand Winners awards recognise the best athletes in each category, giving karatekas a special uniform with golden embroidery on the shoulders.

Due to the COVID-19 pandemic affecting the 2020 season, the World Karate Federation decided to extend the Grand Winners' term to 2021.

Spain's Sandra Sánchez, Turkey's Serap Özçelik Arapoğlu, China's Xiaoyan Yin, Azerbaijan's Irina Zaretska and Ayumi Uekusa of Japan are the current Grand Winners in female categories.

Ryo Kiyuna of Japan, Kazakhstan's Darkhan Assadilov, France's Steven Dacosta, Turkey's Uğur Aktaş and Iran's Sajad Ganjzadeh are the current male Grand Winners.

Seven of those are set to compete in Istanbul, including world champions Sánchez and Zaretska, as well as home favourites Arapoğlu and Aktaş.

Spain's Sandra Sánchez is one of the Grand Winners who will be in attendance for the Istanbul Karate 1-Premier League ©Getty Images
Spain's Sandra Sánchez is one of the Grand Winners who will be in attendance for the Istanbul Karate 1-Premier League ©Getty Images

There are nine world champions in total entered for the tournament in Turkey's biggest city, including Jonathan Horne of Germany and Bahman Asgari Ghoncheh of Iran.

The 2020 and 2021 Karate 1 standings will be merged to determine the next Grand Winners.

Istanbul is set to host the competition from tomorrow until Sunday (March 14) and will be the first international event since the COVID-19 pandemic.

The last international competition was over a year ago in Salzburg in Austria, which ended on March 1.

Nearly 600 countries from 72 countries are registered to compete in Turkey.