The men's 50m freestyle final was his fourth 50m free race of the day, and his third in less than two hours at the Neo Garden 14th Singapore National Swimming Championships (SNSC) last night.

Teong Tzen Wei still managed to win the blue-riband race at the OCBC Aquatic Centre in a personal best of 22.52sec. His effort was just 0.05sec off Joseph Schooling's national mark -commendable, given the 21-year-old did not taper off for this meet, and was in hard training for the upcoming Asian Games.

"I had a good start but felt myself getting a bit tired in the last 15m," said the AquaTech Swimming athlete. "But I just fought on because I didn't want to lose on home ground to a foreign swimmer."

Teong and the 50m sprinters took on the Mare Nostrum Monaco format, introduced for the first time at the SNSC. While swimmers compete in up to three races for an event at traditional meets - heats, semi-finals and finals - the Mare Nostrum format features a knock-out format whereby one could swim up to four races, with the final featuring five, instead of eight, swimmers.

"It is the first time I am competing in this format and this is interesting and fun," said Quah Ting Wen, who won the women's 50m butterfly in 27.20sec.

Roanne Ho, who won the women's 50m breaststroke in 31.61sec, added: "It trains you to be a more efficient swimmer. You can use your previous races to learn for your next one. But it was more tiring than I thought it would be."

National head coach Stephan Widmer was pleased that the swimmers managed to perform well despite their fatigue.

The Australian said: "In order to perform at a higher level, you have to be incredibly comfortable (despite) being super-uncomfortable.

"Some of these guys could barely walk to the starting block... but what was essential to me about this 50m series is that they learn and understand that they can perform regardless of what they feel or what their bodies tell them. I want them to believe in their abilities and gain confidence from there."

Distance swimmer Glen Lim set a national record of 3min 54.12sec when he won the men's 400m free and felt he could go faster at the Asian Games. It was his second national mark at the meet, after clocking 8:15.08 to rewrite the 800m free record on Wednesday.

The 16-year-old said: "It's all in the mind for me. If I have the mental strength and take it to the Asian Games, I could go maybe two seconds faster."