Passage 5.8.4
ἡνιόχει δὲ καὶ ἄλλως ὁ Ἰόλαος Ἡρακλεῖ τὰς ἵππους· αὐτός τε οὖν ἅρματι καὶ Ἰάσιος ἀνὴρ Ἀρκὰς κέλητος ἐνίκησεν ἵππου δρόμῳ, Τυνδάρεω δὲ οἱ παῖδες ὁ μὲν δρόμῳ, Πολυδεύκης δὲ πυκτεύων. λέγεται δὲ καὶ ἐς αὐτὸν Ἡρακλέα ὡς πάλης τε ἀνέλοιτο καὶ παγκρατίου νίκας.
Iolaus also served otherwise as a charioteer, driving horses for Heracles. Hence, he personally won with his chariot, while Iasius, an Arcadian man, won the mounted horse-race. Among the sons of Tyndareus, one was victorious in the foot-race, while Polydeuces prevailed in boxing. It is also said that Heracles himself won victories in both wrestling and the pankration.