The History of the Grecian War (1.105.4-1.105.6)

But the Athenians stirred not from Aegina; but those that remained at Athens, both young and old, under the conduct of Myronides went to Megara;

and after they had fought with doubtful victory, they parted asunder again with an opinion on both sides not to have had the worse in the action.

And the Athenians, who notwithstanding had rather the better, when the Corinthians were gone away erected a trophy. But the Corinthians, having been reviled at their return by the ancient men of the city, about twelve days after came again prepared and set up their trophy likewise, as if the victory had been theirs. Hereupon the Athenians sallying out of Megara with a huge shout both slew those that were setting up the trophy and, charging the rest, got the victory.