Against which player did Djokovic lose his first Grand Slam final?

Novak Djokovic lost his first Grand Slam final to Roger Federer at the 2007 US Open. The 20-year-old Serbian was appearing in his first major final, while Federer was the world No. 1 and the defending champion.

Federer won 7–6, 7–6, 6–4 on the hard courts of New York. Djokovic had chances in both opening sets, including set points, but Federer’s serving and composure in the tie-breaks proved decisive. The result gave Federer his fourth consecutive US Open title.

Despite the defeat, the match marked Djokovic’s arrival at the highest level. Earlier that summer, he had defeated Federer in the Montreal final, showing that he could challenge the dominant champion. Djokovic would later defeat Federer in several major finals, including the 2015 Wimbledon and US Open finals. The 2007 final therefore began one of the defining rivalries of the modern era rather than serving as a measure of Djokovic’s eventual ceiling.