If you check the scores of Halep's matches in Sofia, you'll see the sets she played with Alizé were the most close. Stosur and Ivanovic may have taken a set to Halep, but lost the two others without winning more than 2 games for each. Alizé took 4 games in each set. She played well, and she could even play better.
Alizé. She's a great fighter, and gives everything. She's worth the title of French number one in the paths of Marion.