Slutskaya made a successful comeback in the 1999–2000 season. In December 1999, she defeated Butyrskaya, the reigning World champion, to win her first Russian national title. The following month, she won the Grand Prix Final, defeating both Butyrskaya and Kwan. In second place behind Kwan ahead of the two-women "super final," Slutskaya landed seven triples in the final segment, including two triple-triple combinations, and became the first woman to perform a 3Lz-3Lo combination in competition. In February, she won her third European title, in Vienna, Austria. At the 2000 World Championships in Nice, France, Slutskaya won her qualifying pool over Kwan and placed second to Butyrskaya in the short program. She completed six triples in the free skating, with a 2S instead of her planned 3S-3Lo, and finished second overall behind Kwan.