Asteropaios, (Akessamenos) had the distinction in combat of being ambidextrous and would on occasion throw two spears at once. In Book XII of the Iliad as the Trojans attack the Achaean wall, Asteropaios is a leader of the same division as the Lycian warriors Sarpedon and Glaucus, the division which pressed hard enough to allow Hector and his division breach in the wall.

In book XXI, as Achilles is mercilessly slaughtering Trojan warriors alongside the river Skamandros and polluting the waters with dead bodies (including one of Priam's sons, Lycaon), the river god in turn encourages Asteropaios to make a stand against Achilles.

Achilles and Asteropaios thus engage in one-on-one combat, Asteropaios throwing two spears at the same time at Achilles. One spear hits Achilles' shield, while the other reaches his right forearm and draws blood. Thus, Asteropaios is the only Trojan in the Iliad who was able to draw blood from Achilles. However, he ultimately fails to kill Achilles, and is slain. Later, in the funeral games for the slain Patroclus, the armour of Asteropaios is awarded as prizes.

There is also an asteroid called Asteropaios named after the hero.