Kuznetsova fought back from a set down but still lost
French Open champion Svetlana Kuznetsova continued her run of poor form with a second-round loss to Maria Kirilenko at the Italian Open in Rome.
The world number five was beaten 6-2 3-6 6-4 by her fellow Russian.
Kuznetsova, 25, has now won just three of her last seven matches as she prepares to defend her title at Roland Garros later this month.
"I found it hard to play," she said. "I didn't have many matches this year. I still have to find myself out there."
In the first round, Italian 13th seed Francesca Schiavone fought back from a set down to beat Daniela Hantuchova of Slovakia 3-6 6-2 6-2.
Shahar Peer, the Israeli 16th seed, eased into the second round with a 6-2 6-1 win over Corinna Dentoni of Italy, while there were also wins for 11th seed Yanina Wickmayer and 12th seed Flavia Pennetta.
World number one Serena Williams makes her return in the tournament later this week, having been out of action with a knee injury since winning the Australian Open in January.
Her second-round opponent will be Swiss Timea Bacsinszky, who beat Czech Sandra Zahlavova 6-0 6-4.
Serbia's Ana Ivanovic, who has slipped to 58th in the rankings after winning the French Open and becoming world number one in 2008, eased into round two with a 6-1 6-3 victory over world number 32 Elena Vesnina of Russia.
Ivanovic recently hired Steffi Graf's old coach, Heinz Gunthardt, and is optimistic about returning to the top 10.
"We made a plan when we started working together a couple months ago and it's working really well," said Ivanovic.
"It's going to take some time but I really believe I'm going to be back."