Recording their first-ever win at the FIFA Beach Soccer World Cup through a last-gasp Agustin Ruiz volley, the Central Americans moved level on to three points with Argentina in Group B, while Portugal have booked their place in the quarter-finals.
The first period began slow, with each side relying on long-range passes from the back to create some rare chances. However, with a few seconds remaining, Oman snatched the lead through Jalal Al Sinani.
The Salvadorans were searching for an equaliser, and assumed control of the match in the second period. Elias Ramirez fired a low shot to draw things level at 1-1, before an intriguing third period came to fruition.
El Salvador took the lead at the restart thanks to Tomas Hernandez and an own-goal from Nasse Al Muhaini, who mishandled an attempt to dispossess Frank Velasquez. But Hani Al Dhabat headed home in the 33rd minute to give Oman hope, before Jalal scored his second to level the score.
The match appeared headed for extra time, but an incredible late winner from Agustin sealed a memorable first victory for El Salvador at these finals.