Lilyana was born in Plovdiv, and represented the club Trakiya Plovdiv. She won a silver medal in a 4 x 392 metres relay race at the 1974 European Indoor Championships. She also reached the final of the 800 metres event, but did not finish the race. At the 1974 European Championships in the summer she won the gold medal in the 800 metres and silver in the 1500 metres. In winning gold she beat the reigning Olympic 800 metres bronze medallist Gunhild Hoffmeister by 0.67 seconds, but Hoffmeister won the 1500 metres.