Unlikely winners can be described using various synonyms depending on the context of the situation. Some of the synonyms for unlikely winners are underdogs, long shots, dark horses, outsiders, and surprise champions. Underdogs are those who are expected to lose, but they manage to win against all odds. Long shots are those with a slim chance of winning. Dark horses are those who are not known to be contenders but surprisingly win. Outsiders are those who are not part of the favored group but still manage to win. Surprise champions are those who are not widely expected to win, but they end up taking the victory. These synonyms can be used interchangeably, but the context determines which one fits best.