Williams said she never considered retiring from the match.
However, McEnroe, leading 6-3, injured his ankle and had to retire from the match.
He began gathering his racquets in a threat to retire from the match.
The injury forced Golovin to retire from the match.
Yet Venus said she never considered retiring from the match.
Leading 6-3, 2-3, Roddick suffered a groin injury and was forced to retire from the match.
"I thought I had simply retired from the match," he said.
She retired from the match because of a back injury sustained before the match started.
She retired from the match in tears, sending Serena into the semis.
Ferreira retired from the match and was carried off the court on a stretcher.