Diodorus of Sicily: Greek historian, author of the Library of World History. His activities can be dated between 60 and 30 BCE.
In the first weeks of 325, Alexander was almost mortally wounded, the Greek settlers in Sogdia revolted, and the way back home seemed impossible. Tensions between various groups in the army and at court, for example between Greeks and Macedonians, were high and exploded when Alexander was in Alexandria (Uch). The fight between Dioxippus and Coragus illustrates this.
The Greek author Diodorus of Sicily, describes it in section 17.100.2-101.6 of his World History. The translation is by C. Bradford Welles.
Dioxippus and Coragus
[17.100.2] In the course of the drinkingnote[During a banquet.] a curious event occurred which is worth mention. Among the king's companions there was a Macedonian named Coragus, strong in body, who had distinguished himself many times in battle. His temper was sharpened by the drink, and he challenged to single combat Dioxippus the Athenian, an athlete who had won a crown in the foremost games.note[Winner of boxing during the Olympic games of 336.]
[17.100.3] As you would expect, the guests at the banquet egged them on and Dioxippus accepted. The king set a day for the contest, and when the time came, many myriads of men gathered to see the spectacle.
[17.100.4] The Macedonians and Alexander backed Coragus because he was one of them, while the Greeks backed Dioxippus. The two advanced to the field of honor, the Macedonian clad in his expensive armor
[17.100.5] but the Athenian naked, his body oiled, carrying a well-balanced club. Both men were fine to look upon with their magnificent physiques and their ardour for combat. Everyone looked forward, as it were, to a battle of gods. By his carriage and the brilliance of his arms, the Macedonian inspired terror as if he were Ares, while Dioxippus excelled in sheer strength and condition; still more because of his club he bore a certain resemblance to Heracles.note[Alexander's alter ego.]
[17.100.6] As they approached each other, the Macedonian flung his javelin from a proper distance, but the other inclined his body slightly and avoided its impact. Then the Macedonian poised his long lance and charged, but the Greek, when he came within reach, struck the spear with his club and shattered it.
[17.100.7] After these two defeats, Coragus was reduced to continuing the battle with his sword, but as he reached for it, the other leaped upon him and seized his swordhand with his left, while with his right hand the Greek upset the Macedonian's balance and made him lose his footing.
[17.100.8] As he fell to the earth, Dioxippus placed his foot upon his neck and, holding his club aloft, looked to the spectators.
[17.101.1] The crowd was in an uproar because of the stunning quickness and superiority of the man's skill, and the king signed to let Coragus go, then broke up the gathering and left. He was plainly annoyed at the defeat of the Macedonian.
[17.101.2] Dioxippus released his fallen opponent, and left the field winner of a resounding victory and bedecked with ribands by his compatriots, as having brought a common glory to all Greeks. Fortune, however, did not allow him to boast of his victory for long.
[17.101.3] The king continued more and more hostile to him, and Alexander's friends and all the other Macedonians about the court, jealous of the accomplishment, persuaded one of the butlers to secrete a golden cup under the pillow;note[Of his banqueting couch.] then in the course of the next symposium they accused him of theft, and pretending to find the cup, placed Dioxippus in a shameful and embarrassing position.
[17.101.4] He saw that the Macedonians were in league against him and left the banquet. After a little he came to his own quarters, wrote Alexander a letter about the trick that had been played on him, gave this to his servants to take to the king, and then took his own life. He had been ill-advised to undertake the single combat, but he was much more foolish to make an end of himself in this way.
[17.101.5] Hence many of those who reviled him, mocking his folly, said that it was a hard fate to have great strength of body but little sense.
[17.101.6] The king read the letter and was very angry at the man's death. He often mourned his good qualities, and the man whom he had neglected when he was alive, he regretted when he was dead. After it was no longer of use, he discovered the excellence of Dioxippus by contrast with the vileness of his accusers.