History of the Peloponnesian War

And on that occasion the cart was already at the gates, and on their being opened in the usual manner for the skiff, as they thought, the Athenians, (for this had been done by agreement with them,) on seeing it, ran full speed from their ambush, wishing to reach the spot before the gates were shut again, and while the cart was still in the entrance, and prevented their being closed; the Megareans who were in concert with them at the same time dispatching the guard at the gate.

Demosthenes with his Plataeans and peripoli were the first to run in, (at the point where the trophy now stands,) and as soon as they were within the wall, (for now the nearest Peloponnesians were aware of it,) the Plataeans engaged with and defeated those who came to the rescue, and secured the gates for the advancing heavy-armed of the Athenians.

Then each of the Athenians, as he successively entered, proceeded against the wall.