Both competitions entered the round of 64 stage and both favourites were in ominous form as they cruised into the next round.

Hirano brushed aside Germany's Caroline Hajok 11-3, 13-11, 11-8, 11-8 in straight games while Harimoto overcame Valentin Pieraert of Belgium 11-5, 9-11, 11-3, 11-4, 7-11, 11-5.

As a result of her win, Hirano, the 16-year-old who defeated Chinese Taipei's Cheng I-Ching in straight games to become the youngest women's World Cup champion in Philadelphia earlier this year, will now take on Russian Valeria Shcherbatykh in the final 32 after she defeated Canadian Justina Yeung 13-11, 11-3, 8-11, 11-4, 11-2.

There was further Japanese success further down the draw as Mima Ito also advanced courtesy of a convincing 11-8, 11-8, 10-12, 11-6, 11-4 win over Belgian Eline Loyen.

Romanian Adina Diaconu was also in impressive form as she secured her place in tomorrow's action.

The seventh seed defeated the Czech Republic's Marketa Sevcikova, seeded seventh, 12-10, 11-7, 11-5, 8-11, 11-2.

Joining Harimoto's in the next round of the boy's competition is his compatriot Yuto Kizukuri after he dispatched Czech player Patrik Klos 11-8, 11-4, 11-4, 4-11, 11-7.

Second seed Seungmin Cho was also in dominant form as he made light work of Abdullah Yigenler of Turkey.

Cho came through the contest with ease, winning 11-5, 5-11, 11-8, 11-7, 11-4.

Elsewhere on a busy day of action, Frenchman Irvin Bertrand beat Spaniard Carlos Vedriel in straight games.

In the opening stages, however, neither player could be separated with Bertrand eventually taking a length first game 19-17. 

From then on, the French player's confidence grew and he proved too strong for Vedriel.

Bertrand took the remaining three games he needed to progress 11-5, 11-4, 11-6.

The tournament in Cape Town is due to continue tomorrow with round of 32, 16 and quarter-final action due to take place in both singles competitions.