IT IS the enduring downside to any friendly rivalry and yesterday, it was Amanda Lim who had to play second fiddle.

The latest chapter of what is growing into Singapore swimming's most keenly-fought duel was won by Quah Ting Wen. She pipped her compatriot to the 50m freestyle gold medal by a quarter of a second.

The 16-year-old bagged her second Asian Youth Games gold with a 25.43sec effort, adding to the one she picked up for the 200m free on Friday in a national record-breaking time.

Yet, it was Singapore Sports School student Amanda, competing in the very pool she has trained in nearly every day for the past four years, who started as the pre-race favourite.

She had bettered Ting Wen's national and Under-17 record of 25.65sec in Saturday's semi-final. Her 25.38 topped the qualifying timesheets, while Ting Wen was second-fastest (25.54).

But yesterday, the Raffles Institution (Junior College) first-year student's quicker reaction time - 0.64sec to Amanda's 0.67 - gave her the early edge.

The pressure of the big stage revealed who could cope - Amanda's strokes in the first 15m were hurried, while her teammate's smooth movement showed her composure.

Although Hong Kong's Stephanie Au ((26.22) was always going to be a potential threat, by the halfway mark, it was obvious that she was not going to match the pace of the two Singaporeans.

Ting Wen began to pull away with 20m to go, but, in the end, was just unable to go under Amanda's record.

'For sprints, it's really anyone's race,' said the 1.74m-tall Ting Wen, who credited Amanda for helping to calm her nerves in the waiting room.

'To be able to talk to each other before the race really helped. We talked about school, the upcoming World Championships, actually about anything except the race.'

Amanda chipped in: 'This is the only AYG event we could get a 1-2 in, and we're really happy to achieve it.'

The pair have known each other since the age of 10, competing in inter-school and national age-group meets.

But while the 1.69m-tall Amanda has focused on the sprints for several years, it was only last year that her teammate made the switch from the distance events.

Their tussle over the national and U-17 50m mark has seen the record fall five times since June 2008, a sign of how keen the competition has been.

AYG head coach David Lim calls the duel a healthy rivalry.

Ting Wen agrees.

She said: 'I don't see Amanda as a threat. We're swimming for Singapore together. It's nice that one of us has the record, and another the gold.'

The hosts had another reason to celebrate yesterday.

The quartet of Rainer Ng, Lionel Khoo, Dzulhali Kamal and Clement Lim were third in the boys' 4x100m medley relay in 3min 52.59sec.

South Korea's Jung Wonyong, Gil Byeong Hwi, Chang Gyu Cheol and Kwon Oh Kook were first (3:50.04), and China's Lang Yuanpeng, Sun Yuchen, Liu Chang, and Huang Zhenghan second (3:51.94).

The Koreans' gold was one of five from yesterday's seven finals, as the Asian powerhouses continued their dominance in the pool.

Aided by Beijing Olympians Jung Ha Eun and Kang Yeong Seo, they top the swimming medal tally with 11 golds, 10 silvers and three bronzes.

China, the 2006 Asian Games swimming champions, have sent a developmental squad and lie second (5-5-5).

Singapore are third (3-1-5).

Ting Wen's gold also took the Republic's total number of golds to five.

But the Republic have all but exceeded expectations, including that of Senior Parliamentary Secretary (Community Development, Youth and Sports) Teo Ser Luck.

In today's final day of competition, the hosts still have gold-medal prospects in bowling and swimming.

Mr Teo said: 'Any medal now is a bonus. We've shown that we can compete with Asia's top sporting nations.

'But the bigger issue is how to retain the talent and continue to groom them.'

limze@sph.com.sg