In the course of his Eleventh Labor on his way to the Garden of the Hesperides, Herakles comes to Libya and encounters the giant Antaios. Herakles is forced into a wrestling match whereby the giant plans to add the hero's skull to his growing collection of grappling trophies, with which he plans to build a temple to his father Poseidon. Herakles discovers that Antaios' strength comes from contact with the earth (his mother Gaia) and manages to lift him off the ground and asphyxiate him.
According to Henle (p. 69, Greek Myths, A Vase Painter's Notebook), the scene of Herakles and Antaios wrestling "comes late into the pictorial tradition and, perhaps for this reason, has no type. It is simply a scene of wrestling, varied as different holds and throws are used. Herakles' attributes often hang on the wall of the vase or lean against it, but the scene is essentially a slice of the life of the palestra."
For these varied positions in both black- and red-figured vases, see nos. 1-28 in Olmos and Balmaseda, "Antaios" in LIMC, vol. I.
The Daybreak Painter, a member of the Leagros group, was identified by Haspels. For a lekythos by this painter with the same subject, now in Munich, see no. 196.3, pl. 17.2 in Haspels, Attic Black-Figured Lekythoi.