Vera Zvonareva reached her first WTA Tour semi-final since January with victory over Francesca Schiavone at the DFS Classic in Birmingham.
Zvonareva's ranking has slipped over the past two years
Zvonareva kept up her good form on grass with a 6-4 3-6 6-1 win over the Italian second seed.
The Russian has fallen to 77th in the world rankings, after being as high as ninth in August 2004.
Meanwhile, Maria Sharapova kept up her hopes for a third consecutive DFS title after victory over Mara Santangelo.
The world number four cruised to a comfortable 6-2 6-2 win in 67 minutes to maintain her new-found status as the sport's most successful player - in percentage terms - on grass.
Sharapova has now won 34 of 37 matches on the surface for a winning percentage of 91.9%, with her run in this week's tournament taking her past the previous best mark held by Steffi Graf of 91.5%.
She will face Jamea Jackson, who beat Elena Likhovtseva 6-4 6-3.
In the first set of her match, Zvonareva gained the crucial break in the third game, and from then on she remained in control.
In the second set, however, the suspect temperament which has seen her slide down the rankings came to the fore as she questioned calls and was seen constantly muttering under her breath at decisions and shots.
After being broken by Schiavone in the eighth game, she twice hammered her racket into the ground and then her bag.
But the three-time WTA Tour title winner regained her composure in the final set, twice breaking Schiavone.
She will face another unseeded player, American Meilen Tu in the semi-finals.
Tu put in a sparkling performance to defeat number six seed Marion Bartoli 6-4 6-4.