Agus Prayogo and Odekta Elvina Naibaho triumphed in their races to help bring their nation up to second in the overall medals table, behind only the hosts.

Prayogo secured his seventh gold at the Games with a win in the men's edition in 2hour 32min 59sec.

The picturesque route saw runners weave through the iconic Angkor Wat on a sweltering day.

He was followed across the line by Filipino Arlan Estobo Arbois, with a time of 2:33:27, before Vietnam's Nguyen Thanh Hoang secured the bronze medal in 2:35:27.

The event saw Naibaho finish first in 2:48:14 before Vietnam's Thi Tuyet Le and Christine Organiza Hallasgo followed suit in 2:49:21 and 2:50:27, respectively.

Further athletics success came for Indonesia courtesy of Hendro Yap who secured gold in the men's 20-kilometres race walk.

Yap clocked in after 1:40:42 to beat Vietnamese silver medallist Nguyen Thanh Ngung and Pyae Phyo Htun of Myanmar.

Over at the Morodok Tech Stadium's Aquatics Centre, there was an eventful first day of swimming with Singapore claiming the majority of the medals. 

Singapore dominated the men's 100-metres freestyle final with personal bests from Tan Jonathan Eu Jin and Quah Zheng Wen in 48.80 and 48.99 to finish first and second respectively.

Quah dropped a spot from 2021 whereas Tan improved on his previous SEA Games effort after tying for second last time round with the third placed athlete today, Luong Jeremie Loic Nino of Vietnam.

"First race, so the nerves were there, plus we didn't really get a morning swim to settle in and that affected it a bit," Quah said.

"But happy to get the first race out of the way, looking forward to the next races, the confidence is there."

Although today is officially day one, a total of nine gold medals were won before the Opening Ceremony.

As a result, Cambodia currently top the standings with 17 golds while Indonesia occupy second on eight victories and Thailand's seven puts them in third.

A bumper day of action is in store tomorrow with 47 golds set to be won.