2025 Keio Challenger – Men's singles

Men's singles
2025 Keio Challenger
Final
Champion	Rei Sakamoto
Runner-up	Kaichi Uchida
Score	4–6, 7–6(7–4), 6–4
Events
Singles men women Doubles men women
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Main article: 2025 Keio Challenger

Yuta Shimizu was the defending champion ^[1] but lost in the second round to Yusuke Kusuhara.

Rei Sakamoto won the title after defeating Kaichi Uchida 4–6, 7–6^(7–4), 6–4 in the final. ^[2]

Seeds

1. Kei Nishikori (quarterfinals)
2. Rei Sakamoto (champion)
3. Elias Ymer (first round, retired)
4. Oliver Crawford (first round)
5. Hsu Yu-hsiou (first round)
6. Yuta Shimizu (second round)
7. Yasutaka Uchiyama (quarterfinals)
8. Kaichi Uchida (final)

Draw

Key

• Q = Qualifier
• WC = Wild card
• LL = Lucky loser
• Alt = Alternate
• ITF = ITF entry
• PR = Protected ranking
• SR = Special ranking
• SE = Special exempt
• JE = Junior exempt
• JR = Junior Accelerator Programme entrant
• CO = College Accelerator Programme entrant
• NG = Next Gen Accelerator Program entrant
• w/o = Walkover
• r = Retired
• d = Defaulted

Finals

	Semifinals							Final
	8	Kaichi Uchida	6	6
	Q	Igor Marcondes	4	2
								8	Kaichi Uchida	6	64	4
								2	Rei Sakamoto	4	77	6
		Akira Santillan	6	1	3
	2	Rei Sakamoto	3	6	6

Top half

	First round							Second round							Quarterfinals							Semifinals
	1	K Nishikori	4	6	6
	Q	T Ichikawa	6	1	1			1	K Nishikori	6	6
	WC	Lennon Roark Jones	6	1	2				S-h Shin	4	1
		Shin San-hui	3	6	6										1	K Nishikori	2	2
		M Jones	63	2											8	K Uchida	6	6
	Q	Ryotaro Taguchi	77	6				Q	R Taguchi	5	4
		H Chung	3	0				8	K Uchida	7	6
	8	K Uchida	6	6																		8	K Uchida	6	6
	4	O Crawford	4	4																		Q	I Marcondes	4	2
	Q	I Marcondes	6	6				Q	I Marcondes	6	77
	Q	Jumpei Yamasaki	4	65					Y Mochizuki	2	65
		Yuki Mochizuki	6	77											Q	I Marcondes	6	6
		Max Basing	6	2	3											N Oberleitner	1	3
		Hikaru Shiraishi	2	6	6				H Shiraishi	5	6	3
		N Oberleitner	7	6					N Oberleitner	7	4	6
	5	Y-h Hsu	5	2

Bottom half

	First round							Second round							Quarterfinals							Semifinals
	6	Y Shimizu	6	6
		Y Takahashi	2	2				6	Y Shimizu	3	3
		K Isomura	5	3				Q	Y Kusuhara	6	6
	Q	Y Kusuhara	7	6											Q	Y Kusuhara	3	2
		A Santillan	6	6												A Santillan	6	6
	WC	M Imamura	0	2					A Santillan	6	6
	JR	K Bigun	3					JR	K Bigun	3	1
	3	E Ymer	0r																				A Santillan	6	1	3
	7	Y Uchiyama	6	713																		2	R Sakamoto	3	6	6
		T-h Huang	4	611				7	Y Uchiyama	6	6
		Shin Woo-bin	3	3				Q	M Vrbenský	3	3
	Q	M Vrbenský	6	6											7	Y Uchiyama	6	3	4
		Maxim Zhukov	6	6											2	R Sakamoto	3	6	6
	WC	Ryo Tabata	4	4					M Zhukov	1	2
		K Samrej	4	61				2	R Sakamoto	6	6
	2	R Sakamoto	6	77

References

1. Heer, Florian (November 30, 2023). "Watanuki Wins Yokohama Keio Challenger".
2. "Sakamoto Secures Yokohama Keio Challenger Crown". tennistourtalk.com. Retrieved 23 November 2025.

External links

• Main draw
• Qualifying draw