He began training for distance events only three months ago, so Wong Zhi Wei was pleasantly surprised at just how quick he was in the 400m freestyle (S11-S13) at the Asian Youth Para Games (AYPG) in Dubai yesterday.

The 15-year-old, who is partially blind, left the field in his wake with a personal best of 5min 5.05sec, over a minute faster than Alireza Amirimargavi of Iran (6:47.58), the fastest of his seven rivals.

"Swimming the 400m free is new for me as I started out as a sprinter. But my coach Roland Tan wanted me to be more versatile, so he's been teaching me things like cardio endurance and how to have a more efficient stroke in the last three months," said Zhi Wei, who swims in the S13, the least severe of the three categories for athletes with visual impairment.

"I was fortunate to be in Lane 1 today. I could see where the others were when I popped my head up and this helped me to pace myself, and to start and finish strong."

The 400m free gold adds on to the gold and silver he won on Monday in the 100m butterfly and 100m backstroke respectively.

Yesterday, compatriot Danielle Moi also won a silver (1:15.59) in the women's 100m fly (S14).

Swimming was not the only sport to strike gold - there was joy on the track as well for Lionel Toh, who won the men's 100m (T37) in 14.20sec on Monday (early yesterday morning, Singapore time).

For Zhi Wei, his stellar showing at the AYPG so far has him looking ahead to the future with increased self-belief, with distance events now part of the plan.

The Catholic High Secondary 3 student's 400m free time was 25 seconds off the Asian S13 record held by Japan's Uchu Tomita (4:39.55).

"My coach and I are working on a three-to four-year timeline and I really hope to qualify for the Tokyo 2020 Paralympics," he said.

"The priority is (my pet) 100m fly but also the 400m free now. My personal best today has definitely showed me that I can go even faster in the long distances."

The quadrennial Games, which have attracted 715 participants from 30 teams, end today.