For two hours, Li had struggled against her hard-hitting opponent. Trailing 5-6 in the third set, she walked to the baseline knowing that she had to break serve just to stay alive. Lose the next four points, and she might carry out her pretournament threat to quit the sport she had been forced to start playing nearly a quarter-century ago. Her spring season had been a bruising free fall from the heights of her second Australian Open final in January to her second-round flameout at the French Open in May. Now the graveyard was calling.