| Event |
|---|
| 400 m MEDLAY - BOYS - FINAL |
| Rec | Name | NOC | Year | |
|---|---|---|---|---|
| ASG REC | 4 m 34.79 s | NGUYEN DANG KHOA | VIE | 2017 |
| Pos | Lane | Name | NOC | Time | Notes |
| 1 | 6 | SEBASTIAN SOON | MAS | 4 m 30.85 s | CR |
| 2 | 9 | ATHALARIK MAULIDIO FERNANDO | INA | 4 m 33.11 s | |
| 3 | 7 | KHIEW HOE YEAN | MAS | 4 m 40.59 s | |
| 4 | 3 | TAN EPHRAIM | SGP | 4 m 43.48 s | |
| 5 | 8 | ARDI ZULHILMI BIN MOHAMED AZMAN | SGP | 4 m 50.12 s | |
| 6 | 1 | DANIEL SETYAWAN S | INA | 4 m 53.48 s | |
| 7 | 5 | DE GUZMAN, GIAN KARLO M. | PHI | 5 m 08.93 s | |
| 8 | 2 | GO, ETHAN ROY R | PHI | 5 m 12.22 s | |
| - | 2 | NGUYEN NAM | VIE | DNF |