Who was the opponent when Roger Federer won his 100th career ATP title?

Stefanos Tsitsipas was Roger Federer’s opponent when Federer won his 100th career ATP singles title. Federer defeated Tsitsipas 6–4, 6–4 in the 2019 Dubai Tennis Championships final.

The milestone made Federer only the second man in the Open Era to reach 100 ATP singles titles, after Jimmy Connors. Federer had already won his 99th title at the 2018 Swiss Indoors in Basel, so the Dubai final marked a historic move into triple digits.

The victory was also Federer’s eighth Dubai title. He had previously won the tournament in 2003, 2004, 2005, 2007, 2012, 2014 and 2015. The match was played on hard courts, and Federer won without dropping a set in the final.

Tsitsipas was not merely a ceremonial opponent: he was one of the rising stars of the next generation and had defeated Federer at the 2019 Australian Open earlier that year. After reaching the Dubai final, Tsitsipas entered the ATP top 10 for the first time, becoming the first Greek player to do so. Federer later finished 2019 with 103 career singles titles.