It was well past 3am yesterday but Singapore pool player Aloysius Yapp was still buzzing with excitement. Not surprisingly, he was unable to sleep.

There was hardly any disappointment coursing through the 19-year-old even though, hours earlier, he had lost 7-11 to China's former world champion Wu Jiaqing in the World Nine-ball Championship quarter-finals in Doha.

There was no substantial cause for regret because, by reaching the last eight of the prestigious US$200,000 (S$280,000) tournament at the Al-Arabi Sports Club in the Qatari capital, Yapp had recorded the best-ever finish by a Singaporean in the event.

Ranked 43rd in the world and unseeded in the elite 128-man field, he claimed some notable scalps along the way.

He beat world No. 2 Darren Appleton in his opening group match.

He emerged victorious in a tense 11-10 match against European champion Alexander Kazakis in the round of 16.

He told The Straits Times yesterday: "I kept fighting in every round and never gave up.

"Beating the top players has given me a lot of confidence and the belief that I can not only compete at this level, but also succeed."

Yapp also highlighted his 11-9 win over Japan's Naoyuki Oi in the first knockout round as a key moment.

He had spent the majority of the contest trailing his opponent but capitalised on an error when the score was 8-8 to sneak through.

Yapp made history last year with his victory in the Nine-ball World Junior Pool Championships in Shanghai. The feat helped him clinch the 2015 Sportsboy of the Year award.

However, he has struggled to reach similar heights this term.

In June's SEA Games, he was seen as one of the pre-tournament favourites but did not win a medal.

His form since has also been maddeningly inconsistent.

"I was putting too much pressure on myself but this week I was mentally very strong and kept my composure in difficult moments," noted Yapp.

He earned US$5,000 for his efforts in Doha.

National team-mates Toh Lian Han and Goh Chin Teck were knocked out in the rounds of 32 and 64 respectively.

Calling it a "breakthrough" moment for the sport in the Republic, Cuesports Singapore president Christopher Chuah added: "This is testament to the success of our mentoring and developmental programme for the sport.

"His achievement will also spur our other athletes to strive to greater heights."

Yapp will next partner compatriot Chan Keng Kwang when the duo compete in the World Cup of Pool at the York Hall in London from Sept 22-27.

It comes before his final major assignment of the year, November's All Japan Championship in Osaka.

He said: "Hopefully, I can build on this momentum and do even better in my next few tournaments."