This result was not a huge surprise for me as Maria has been struggling with her serve for a while now and against a player like Dominika it is understandable that her serve would break down.
Victoria Azarenka beat a very poor Sloane Stephens in straight sets. Sloane was desparately disappointing and did not mount any kind of significant attack on Victoria's serve.
Victoria now goes through to face Agnieszka Radwanska who beat Garbine Muguruza in straight sets.
In the men's draw Roger Federer beat Jo-Wilfred Tsonga in straight sets. Jo- Wilfred did not play badly just that Roger was able to win those big points when it mattered.
Andy Murray beat the 'lucky loser' Stephane Robert in four sets and he will now play Roger Federer in the quarters for a place in the semi- finals.
Rafael Nadal beat Kei Nishikori in three marginally close sets to make it to the quarter finals.
Kei had chances to win at a least set and he could not take them as Rafa was always able to raise his level and win the match.