Top seed and US Open champion Kim Clijsters was pushed all the way but eventually subdued a gallant Francesca Schiavone of Italy to reach the semi-finals of the $585,000 Luxembourg Open on Friday.
Clijsters edged a tight first set but had to come from 5-2 down in the second before running out a 6-4, 7-5 winner.
She now meets France's Nathalie Dechy after the fourth seed disposed of Slovak Daniela Hantuchova 6-1, 6-4.
In-form Anna-Lena Groenefeld hit back from a set down to shock second seed Nadia Petrova 2-6, 6-3, 6-2.
The German will face another Russian in the semi-final after seventh seed Dinara Safina battled past Roberta Vinci of Italy 5-7, 6-3, 6-4.
Clijsters was quickly into her stride against the combative Schiavone and went up an early break before the Italian hit back to level at 3-3.
A second break was enough to secure the first set for the Belgian but despite breaking in the first game of the second set, she soon found herself 5-2 down.
Schiavone could not maintain her level, though, and Clijsters reeled off five straight games to seal victory.
The Belgian said: "All the other times when I have played her the games were tough with tough rallies.
"Physically she is one of the toughest opponents I have to play because she is physically fit and gets lots of balls back with heavy topspin."
Dechy breezed through the first set against Hantuchova but briefly came unstuck when serving for the match at 5-2 in the second set before finishing the job in her next service game.
A dispirited Hantuchova said: "Everything went wrong with my game. She played really smart, she didn't let me play my game and I couldn't find my rhythm."
Groenefeld, who started the year world-ranked 75, is up to a career-high 23 after reaching the final in Beijing last week.
After her win over world number nine Petrova, she said: "I feel pretty happy because that's my first win against a top 10 player."
