Britain's Heather Watson is out of the Luxembourg Open after losing 6-4 6-3 to Serb Ana Ivanovic in the first round.
The British number two, who reached the Hong Kong Open quarter-finals, lost the first two games to former world number one Ivanovic, 27, ranked 12th.
The 23-year-old, world ranked 54, levelled by breaking back to love but lost the opening set in 28 minutes.
Second seed Ivanovic maintained the pressure and won in 70 minutes in the first meeting between the pair.
Watson won successive games to close to 3-5 in the second set and went 40-0 ahead in the next game, only to lose the next five points, three of them with double faults.
"I was very happy about this victory because I expected a tough match - I know Heather's a great fighter and she can play really well against top players," said Ivanovic, who won the event in 2007.