Clijsters entered 2007 intending to retire at the end of the season, but only ended up playing in five tournaments due to injuries. She won her only title of the year in her first tournament, the Sydney International. The Australian Open was her only Grand Slam event of the season. For the second consecutive season, she lost in the semifinals, this time to top seed Sharapova. Clijsters's last tournament in Belgium was the Diamond Games, where she finished runner-up to Mauresmo for the second year in a row. A hip injury limited Clijsters's remaining schedule. In her last two tournaments, she lost to Li Na in the fourth round of the Miami Open in March and qualifier Julia Vakulenko in her opening match at the Warsaw Open in May. Her last win was against Samantha Stosur in Miami. A few days after losing in Warsaw, Clijsters announced her retirement at the age of 23, forgoing plans to finish the season.