RIO DE JANEIRO - National swimmers Joseph Schooling and Quah Zheng Wen have made history for Singapore after finishing in the top 16 of the men's 100m butterfly heats.

This is the first time that the Republic has two swimmers qualifying for the same semi-finals of an Olympic event.

Schooling clocked 51.41 sec, edging past American great Michael Phelps in his heat and Quah clocked 52.08 at the Olympic Aquatic Centre in Rio.

Schooling, 21, is also the fastest qualifier amongst the 16 semi-finalists.

Schooling said: "It felt like a morning swim, relaxed, easy... I feel Okay, not really tired, just ready for tonight and focused."Earlier at these Games, Quah had reached the semis of the 200m fly, finishing 10th, while Schooling was 16th in the 100m freestyle.

Quah, 19, said: "I feel pretty happy. It's a new personal best. I think I could have executed some things a little bit better, so I'm excited to get back out there and see how it goes."

Both will be bidding for another record, by becoming the first local male swimmer to reach the A final.

Tao Li is the only Singaporean to achieve this feat. She finished fifth in the 100m fly at the 2008 Beijing Games.

The 100m fly semis will start from 10.34am Friday Singapore time.