Boxing's world governing body AIBA has upheld a second appeal in the Olympic boxing tournament and reinstated American welterweight Errol Spence at the expense of India's Krishan Vikas.
To widespread disbelief, Vikas was awarded a 13-11 verdict on Friday despite being dominated by Spence in the closing rounds.
The result appeared to end US interest in the men's boxing tournament, with all nine of their fighters out.
However, AIBA, who on Wednesday overturned the result of the bantamweight fight between Satoshi Shimizu and Magomed Abdulhamidov after the Azeri was given the verdict despite being floored six times in the final round, also found in favour of Spence.
Following a US protest, AIBA's competition jury re-examined the bout and found that Vikas committed nine holding fouls, but was cautioned for only one of them by referee Lars Brovil of Denmark.
Vikas was also found to have spat out his gumshield intentionally during round two, for which he received no warning.
As a result of these findings, the AIBA jury unanimously agreed that Brovil "should have given at least two warnings to the Indian boxer".
Although the findings concluded that Brovil's view was obstructed for the gumshield incident, it was also noted that the US fighter should have been awarded "at least four points" - thus the score was altered to 15-13 in favour of Spence.
Spence had said: "I thought I landed more shots than he did. I gave my everything in the ring so I am not going to hang my head down low today. There's nothing I can do about the decision."
Spence can now guarantee a medal if he beats Russia's Andrey Zamkovoy in his next bout on Tuesday. Defeat would mean the US will for the first time fail to win a men's boxing medal at a Games for which they have entered at least one fighter.
AIBA's decision to overturn a second result is bound to raise questions over the competency of the officials.
Ishanguly Meretnyyazov of Turkmenistan, who refereed the bout between Shimizu and Abdulhamidov, has been sent home, as has an Azeri technical official.
Commenting on the expulsions, AIBA president Dr Ching-kuo Wu said: "I deeply regret that we have had to take these decisions.
However, our main concern has been and will always be the protection of the integrity and fair play of our competitions."