For John McEnroe, a man of impassioned and instantly expressed emotions, hitting with Ingrid Neel was almost a case of love at first tennis stroke.

To introduce herself, Ingrid drew him to the net with a deft drop volley. Then she dared to lob the great Johnny Mac, lofting the ball inches from the baseline.

O.K., McEnroe thought, so this is how you want to play with a four-time United States Open and three-time Wimbledon champion? He retaliated with a drop-shot winner of his own, stepped toward the net, pointed a finger at his audacious new adversary and gave her a look that said, “You cannot be serious!”

But McEnroe could plainly see that, yes, absolutely she was.

“The way she played, the look in her eye, made me think that maybe it was the 2011 version of what I would look like now, only a girl,” he said.