On 19 June 2004 in Plovdiv, Lalova tied with Irina Privalova as the sixth fastest woman in 100 metres history (at that time), recording a time of 10.77 seconds. At the 2004 Summer Olympics, she placed 4th overall in the women's 100m competition, and 5th in the 200m. At the 2005 European Athletics Indoor Championships, she was awarded a gold medal for her time of 22.91 seconds in the 200m.