ATP Tour

Five facts to know about Nishikori's ATP Challenger career

Kei Nishikori announced himself on the professional tennis stage at just 16 years old. Following a standout junior career, Nishikori won his first ATP Challenger main-draw match in 2006 in Guayaquil.

Now, 20 years later, the 12-time ATP Tour titlist Nishikori has retired from professional tennis. Keep reading to learn five facts about Nishikori’s journey at ATP Challenger level, from his early days to how the circuit played an important role in a comeback from injury.

Nearly perfect in Challenger finals
An eight-time Challenger champion, Nishikori first made a final at that level (Carson, California) as a 17-year-old. Nishikori fell short that day, but he would not repeat that result. The Japanese star held a 8-1 record in Challenger finals. His final Challenger triumph came in 2024, when he won the indoor hard-court event in Helsinki, Finland. “It’s been a long time since I won a title,” Nishikori said after winning his first title in 16 months.

Nishikori’s Delray Beach title preceded his first Challenger trophy
There are plenty of career milestones for Nishikori to celebrate. One of his most memorable triumphs perhaps is his first ATP Tour title, which he earned at the Delray Beach Open in 2008. Then 18, and competing in the main draw as a qualifier, Nishikori claimed the title. The teenager overcame home favourite James Blake 3-6, 6-1, 6-4 in the final.

“Last night I tried to imagine winning the final, but I couldn't do it,” said a relieved Nishikori during the trophy ceremony.

Nishikori is one of four players since 2007 to win an ATP Tour trophy before lifting an ATP Challenger crown. Sergiy Stakhovsky, Lucas Pouille and Juan Manuel Cerundolo are also among that bunch.

Third-youngest player to win both ATP Tour title and Challenger trophy in same season
It did not take long for Nishikori to also enter the Challenger winner’s circle. That same 2008 season, two months after he won in Delray Beach, Nishikori triumphed at the Bermuda Challenger, saving two championship points to survive Viktor Troicki.

“I'm too tired to talk,” Nishikori said after his dramatic 2-6, 7-5, 7-6(5) escape over the Serbian. “I can't believe that I have won. At 15/40 down in the third set, I imagined that I was going to lose.”

Nishikori is the third-youngest player (18 years, three months) to win on the ATP Tour and the ATP Challenger circuit in the same season. Only Lleyton Hewitt (17 years, nine months) and Carlos Alcaraz (18 years, two months) completed the feat at a younger age.

He won a Challenger title while unranked in the PIF ATP Rankings
Nishikori underwent arthroscopic left hip surgery in 2022 and after spending 20 months away from competition, he made his return at the Palmas Del Mar Challenger. Receiving a wild card into the main draw, Nishikori went all the way to the title, becoming the first unranked player since 2000 to win a Challenger trophy. Frenchman Gabriel Debru matched that feat in July this year.

“I could not ask for more on this, able to play five matches in a row and my body is okay,” said Nishikori, then 33 years old.

Challenger trophy & US Open SFs in same season
In the past two decades, only two men have won an ATP Challenger title in the same year during which they reached the US Open semi-finals. Kei Nishikori (2018) and Matteo Berrettini (2019).

Nishikori, who reached the US Open in 2014, began the 2018 season by competing at two ATP Challenger events. He suffered a right wrist injury in 2017, shutting down his season in mid-August. Upon returning to action, Nishikori won the Dallas Challenger.

Then, later that year in New York, Nishikori won a five-set quarter-final against Marin Cilic, the same man who defeated the former No. 4 in the 2014 title match. Nishikori fell to eventual champion Novak Djokovic.