In Tokyo, Matteo Berrettini defeated Alejandro Davidovich Fokina 1-6, 7-6, 6-4.

In yesterday’s match of the day, Carlos Alcaraz needed three sets to take down Alex Michelsen, 7-6, 4-6, 6-1.

In a quartet of upsets in Tokyo, Jaume Munar defeated third seed Taylor Fritz 6-7, 6-4, 6-3; Luciano Darderi defeated sixth seed Casper Ruud 7-6, 6-3; and Ugo Humbert defeated fifth seed Brandon Nakashima 6-3, 6-2; Daniel Vallejo upset Rafael Jodar 6-1, 6-3.

At the WTA 1000 in Beijing, Paula Badosa defeated Daria Kasatkina 4-6, 7-6, 6-4.

Xinran Sun, the 16-year-old Chinese player we highlighted in The Daily Theory yesterday, won over Eva Lys by retirement 6-1, 3-0.

Qinwen Zheng, playing before a home crowd against fellow countrywoman Han Shi, won 7-5, 4-6, 6-2.

And, also in Beijing, in a pair of American vs. American first-round matches, Katie Volynets defeated Robin Montgomery 7-5, 7-5, and Ashlyn Krueger took down Sofia Kenin 6-3, 6-3.

In a thoroughly entertaining match on the men’s side in Beijing, Andrey Rublev needed more than two-and-a-half hours to take out Tallon Griekspoor 6-4, 5-7, 7-6.

Also in Beijing, Francisco Cerundolo required nearly three hours to defeat Botic van de Zandschulp 5-7, 6-4, 6-3.

Also in the Imperial City, Roman Safiullin pulled off the day’s upset by defeating fourth seed Flavio Cobolli 6-3, 6-2.

What he said: “Playing in Japan is always a special moment,” an emotional Nishikori told his home crowd. “I wish I could have put in a slightly more convincing performance. But I’m happy I kept fighting right to the end. I’m proud that I didn't give up and played right to the finish.”

Flashback: I first saw Nishikori play live at the 2008 U.S. Open. He was outside the top 100, and it was the first time he had ever won a match at a major. He reached the fourth round. As I watched him dismantle Juan Monaco, I turned to my friend and said, “This guy is going to be top five and win a major.” It was apparent to me that, as a teenager, he already had the assets of veterans on tour. The movement, the incredible acceleration on the forehand, knowing how to use the geometry of the court, and protecting his weaknesses. What I couldn’t see at that point were the many body breakdowns that would come over the course of two decades of professional tennis. They robbed him — and all of us — of some spectacular tennis. Kei Nishikori is truly one of the great “what ifs” of our sport.

The record: Arthur Fils leads the head-to-head record over Frances Tiafoe 2-0.

On the line: Neither player has ranking points to defend, but both have something to prove. Tiafoe wants to show that the deep mental and physical work he did in the off-season last year is a full commitment that didn’t end at the U.S. Open. Meanwhile, Fils, now in the top 10, is looking to put the year back on track after winning Cincinnati, but losing in the first round of the U.S. Open.