Nigeria's Segun Toriola, the number four seed, also progressed smoothly in his matches to finish top of his group at the Kasarani Indoor Arena.

But while the two favoured players enjoyed success, it did not come easy.

Assar eventually overcame Derek Abrefa of Ghana 11-6, 11-13, 11-8, 8-11, 11-4.

Similarly, Toriola was extended the full distance by a determined Algerian, Sami Kherouf, coming through 11-9, 7-11, 11-4, 7-11, 11-8.

"I am yet to appreciate the atmosphere in Nairobi because the high altitude is really affecting the ball," Toriola, seven times an Olympian, said.

"You cannot play any stroke with confidence; the ball can easily go long.

"You have to be careful."

Abrefa and Kherouf both secured quarter-final places against the winners of the groups on the other side of the draw after finishing as runners-up in the first two of the four groups.

Abrefa will now meet Quadri Aruna of Nigeria, quarter-finalist at the 2014 World Cup and Rio 2016 Olympics.

Earlier in Aruna’s day, he was drawn against 17-year-old home player Brian Mutua - who had been a fan of his play for many years.

After winning 11-8, 11-5, 11-7, Aruna offered his young admirer a warm smile and hand shake.

"I knew about Quadri Aruna because of the 2014 World Cup and also when he was named the star player in 2015," said Mutua.

"I admire him and I followed all his matches across the globe.

"He is a player that is respected globally as an African star.

"He has continued to put the continent on the world map with his excellent performances.

"He has been inspirational to younger players and I enjoyed every moment of the match."

In women's action, Algeria's Lynda Loghraibi caused a surprise as she beat Nigeria's Offiong Edem, the fourth seed, 11-8, 11-7, 4-11, 9-11, 12-10.

She had earlier accounted for Nandeshwaree Jalim of Mauritius in an even closer contest, 11-13, 13-11, 11-6, 10-12, 15-13.