Ivanovic's debut at Eastbourne ended in defeat
Ana Ivanovic's Wimbledon preparations suffered a hiccup as she was beaten by Nadia Petrova in the first round of the Aegon International in Eastbourne.
Seven of the world's top 10 are competing at the event, meaning Ivanovic was unseeded and came up against world number 10 Petrova.
The Serb was 4-1 up in the deciding set but lost out 6-1 4-6 6-4.
Top seed Elena Dementieva began her campaign with a comfortable 6-2 6-2 win over fellow Russian Maria Kirilenko.
Dementieva will face Virginie Razzano in the second round after she beat fellow Frenchwoman Alize Cornet 7-6 (7-3) 6-2.
Ivanovic, who split with coach Craig Kardon last week, double-faulted to surrender the break she had earned in the third set.
"I think I could have played a lot better and that is why I was a little bit disappointed because I was practising really well," said the former world number one.
Dementieva, the world number four, twice hit double faults on set points as she struggled to serve in Eastbourne's sea breezes.
But she converted a chance and then began the second set with a break. Another break in the seventh game left her serving for the match and she finished off with a forehand winner.
"It is always fun to play on grass," said Dementieva. "It just takes a longer time before you really feel confident about the movement.
"I think that was a good match for the first one on grass."
In other matches, surprise French Open semi-finalist Samantha Stosur of Australia eased past Germany's Sabine Lisicki 6-2 6-1, and Zheng Jie of China - a 2008 Wimbledon semi-finalist - beat Spain's Carla Suarez Navarro Spain 6-2 6-2.