Sears coached Hantuchová again in 2004 and in 2005, where she won the mixed doubles at the French Open and the US Open. This means she had won all four Grand Slam mixed doubles tournaments. In June 2005, she and Japanese player Ai Sugiyama won a WTA tour doubles tournament in Birmingham, England. The same pair came second in the doubles final at the French Open. Hantuchová won her sixth WTA doubles title with Russian player Anastasia Myskina in Germany in October 2004.