Who was runner-up to Federer in the 2004 US Open men's singles final?

Lleyton Hewitt was runner-up to Roger Federer in the 2004 US Open men's singles final.

Federer won the match 6–0, 7–6, 6–0, capturing his first US Open championship and fourth Grand Slam title. The straight-sets scoreline was unusually emphatic for a major final, especially because Hewitt had been a former world No. 1 and the 2001 US Open champion.

The victory completed a spectacular 2004 season for Federer. He had already won the Australian Open and Wimbledon, becoming the first man since Jimmy Connors in 1974 to win those two majors plus the US Open in the same season. He also became the tenth man to win three Grand Slam singles titles in one calendar year.

Hewitt remained an important figure in Federer's career, but this final was one-sided. Federer would return to win the US Open four more times, while Hewitt never again reached the tournament's singles final.