Don't the rules say something about if there is a 3-way tie with 1 win each, and one player has played fewer matches than the others, she is eliminated? So if Petrova replaced Capriati, and beat Myskina, Petrova would be eliminated. That would make it between Capriati and Myskina. Capriati might also be eliminated by the "fewer matches" rule. And if not, aren't the standings based on wins, not record? Both would have 1 win, and thus it would go to sets W/L, giving Myskina the semi.