Here’s a recap of Tuesday’s action from the USTA Billie Jean King National Tennis Center.

Roger Federer falls to Grigor Dimitrov

Days after Novak Djokovic retired against Stan Wawrinka, another tennis giant fell before the semifinals as Roger Federer lost to Grigor Dimitrov.

Even more surprising than the loss itself might have been the way in which Federer hurt himself. The great committed an incredible 60 unforced errors, 19 more than Dimitrov. He was also only 4-of-14 on break points, missing plenty of opportunities to put the Bulgarian away.

Federer told reporters after the match that he had been dealing with an upper back issue for the entire match, which might explain his struggles.

After four sets of back-and-forth tennis, it was all Dimitrov in the fifth. He won the first four games, leaving Federer in need of some old magic to stay alive in New York. None came.

Dimitrov eventually came out on top 3-6, 6-4, 3-6, 6-4, 6-2, which must have been a cathartic win for a player who has bristled at being called “Baby Federer” in the past.

It has now been 11 years since Federer last emerged victorious at the US Open, his longest drought of any Grand Slam.

Daniil Medvedev reaches semifinals

The Flushing Meadows crowd might not like it, but No. 5 seed Daniil Medvedev is suddenly on the verge of his first career Grand Slam final.

That journey took two major steps on Tuesday when Medvedev topped Stan Wawrinka 7-6, 6-3, 3-6, 6-1 to reach the semifinals, already his best career finish in a Grand Slam.

Medvedev’s chance at the final got much easier with Federer’s loss. The Russian was slated to face the great in the semifinals, now he gets Dimitrov, who looked strong against Federer but has still struggled a bit this year. Likely waiting for either player will be Rafael Nadal, the only No. 2 seed left on his half of the bracket.

Unfortunately, Federer’s loss also means we lose what would have been a surreal scene on Friday night: Medvedev, who flipped off and trolled an entire NYC crowd days ago, playing the universally loved Federer and working to prevent another Federer-Nadal final. The boos would have been legendary.

Serena Williams cruises to semifinals

Serena Williams made quick work of China’s Wang Qiang on Tuesday night.

Very quick work.

Williams easily made it past Qiang, at Arthur Ash Stadium, beating the No. 18 seed in straight sets 6-1, 6-0. The win — which took just 44 minutes, the shortest so far in this year’s tournament —marked her 100th career singles victory at the US Open.

“It’s really unbelievable, literally, because from when I first started here — I think I was 16 — I never thought that I would get to 100. It didn’t even cross my mind or [that] I would still be out here,” Williams said. “But I love what I do. I love coming out with you guys. It’s so special. I never want to let it go.”

She is now just one match win behind Chris Evert’s record of 101 wins, and is 100-12 all-time in the tournament.

Williams held Qiang to just 15 total points won in the match, too, barely letting her gain any momentum whatsoever.

With the win, Williams will now take on Ukraine’s Elina Svitolina in the semifinals — her 10th straight appearance in the round. Svitolina, the No. 5 seed, beat the United Kingdom’s Johanna Konta in straight sets in her quarterfinals match.

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