Photo Credit: Clive Brunskill/Getty

Following several close calls—needing five sets to beat the unseeded pair of Frances Tiafoe and Mikhail Youzhny in the tournament’s first and second rounds, respectively—Roger Federer is out of the U.S. Open, falling to Juan Martin del Potro tonight.

After taking a close first set, 7-5, and dropping the second set, 6-3, the No. 24 del Potro stormed back to take the last two 7-6 (10-8), 6-4. Hardly the comeback heroics required for him to beat Dominic Thiem earlier this week, but exciting all the same:

Del Potro faces Rafael Nadal in the upcoming semifinal, ruining hopes for the Federer-Nadal matchup that seemed so likely in a tournament with so many other big names absent.