Bk XII:327-392 Pirithoüs, Theseus and Peleus join the fight.
"I saw Petraeus trying to tear an oak-tree full of acorns from the ground. While he had his arms round it, bending it this way and that, and shaking the loosened trunk, Pirithoüs sent a lance through his ribs, and pinned his writhing body to the hard wood. They say that Lycus fell by Pirithoüs’s might, and Chromis by Pirithoüs’s might, but Dictys and Helops gave the victor a greater title to fame. Helops was transfixed by a javelin that passed through both temples; hurled from the right and piercing the left ear. Dictys, fleeing in desperate panic, pressed hard by Ixion’s son, stumbled on a mountain height, and fell headlong, breaking a huge flowering ash with the weight of his body, and entangling his entrails in the shattered tree.
Aphareuswas there, his avenger, who tried to hurl a rock torn from the mountainside: but as he tried Theseus, the son of Aegeus, caught him with his oaken club and broke the massive bones of his elbow. Having neither time nor desire to inflict further injury on his worthless body, he leaped onto tall Bienor’s back, unused to carrying anything but its owner, and, pressing his knees into the centaur’s flanks, and clutching the mane with his left hand, he shattered the face, the mouth uttering threats, and the solid temples, with his knotted club. With the club he overthrew Nedymnus, and Lycopes the javelin-thrower; Hippasos, his chest protected by a flowing beard, and Ripheus, who towered above the treetops; Thereus, also, who used to take bears on the mountain slopes of Thessaly, and carry them home angry and alive.
Demoleon could no longer stand the success Theseus was enjoying: he had been trying, with great effort, to tear up the solid trunk of an ancient pine. Unable to do it, he broke it off and hurled it at the enemy. But Theseus drew well away from the oncoming missile, warned by Pallas, or so he would have us believe. The tree trunk did not fall without effect, since it severed tall Crantor’s chest and left shoulder from the neck. He was your father’s armour bearer, Achilles, whom Amyntor king of the Dolopians, having been defeated in battle, gave to Peleus, the Aeacides, as a true pledge of peace.
When Peleus, some distance away, saw him torn apart by the frightful wound he shouted: 'Accept this tribute to the dead, at least, Crantor, dearest of youths,' and with his powerful arm, he hurled his ash spear, at full strength, at Demoleon. It ruptured the ribcage, and stuck quivering in the bone. The centaur pulled out the shaft minus its head (he tried with difficulty to reach that also) but the head was caught in his lung. The pain itself strengthened his will: wounded, he reared up at his enemy and beat the hero down with his hooves. Peleus received the resounding blows on helmet and shield, and defending his upper arms, and controlling the weapon he held out, with one blow through the arm he pierced the bi-formed breast.
Peleus had already, before this, killed Phlegraeos and Hyles, from a distance, and Iphinoüs and Clanis in close conflict. He added Dorylas to these, who wore a wolfskin cap on his head, and instead of a deadly spear, carried a magnificent pair of crooked bull’s horns, dyed red with copious blood.
I shouted to him (my courage giving me strength), 'See how your horns give way before my spear' and I threw my javelin. Since he could not evade it, he blocked a wound to his forehead with his right hand, and his hand was pinned to his forehead. He screamed, but Peleus (as he stood near him) struck him with his sword in mid-stomach, as he came to a halt there, overcome by the harsh wound. Dorylas leapt forward fiercely, dragging his guts on the ground, and as he dragged he trampled them, and as he trampled he tore them, entangled his legs in them, and fell, with emptied belly."