The current average match statistics you find here
The current statistic ranking you find here
I'don't have data from Petrova vs Kirilenko. It's obvious that these data would have a great impact, especially on the statistic ranking.
1. Kirilenko, Maria
2. Henin-Hardenne, Justine
3. Clijsters, Kim
4. Ivanovic, Ana
5. Safina, Dinara (still in the top 5, even after her loss, so it was a good first match a guess)
The predicted draw
Clijsters d Schiavone
Vaidisova d Hantuchova
Henin-Hardenne vs Petrova (no data yet) => ?
Ivanovic d Kuznetsova
Clijsters d Vaidisova
Henin-Hardenne/Petrova d Ivanovic
Henin-Hardenne/Petrova d Clijsters