Growing desperate, he adopted what might be called not an unfair but a mean method of attack: he would manoeuver, leap in and strike swiftly, and then, ducking forward, fall to the ground at Joe's feet.

Joe could not strike him while he was down, and so would step back until he could get on his feet again, when the thing would be repeated.
But Joe grew tired of this, and prepared for him.

Timing his blow with Simpson's attack, he delivered it just as Simpson was ducking forward to fall.

Simpson fell, but he fell over on one side, whither he had been driven by the impact of Joe's fist upon his head.

He rolled over and got half-way to his feet, where he remained, crying and gasping.
His followers called upon him to get up, and he tried once or twice, but was too exhausted and stunned.
"I give in," he said.