2021 Kremlin Cup – Men's singles

Andrey Rublev was the reigning champion from when the tournament was last held in 2019, but lost to Adrian Mannarino in the second round in a rematch of the 2019 final.

Men's singles
2021 Kremlin Cup
Champion	Aslan Karatsev
Runner-up	Marin Čilić
Score	6–2, 6–4
Draw	28 (4 Q / 3 WC )
Seeds	8

Main article: 2021 Kremlin Cup

Aslan Karatsev won the title, defeating Marin Čilić in the final, 6–2, 6–4.

Seeds

The top four seeds received a bye into the second round.

1. Andrey Rublev (second round)
2. Aslan Karatsev (champion)
3. Karen Khachanov (semifinals)
4. Filip Krajinović (second round)
5. Alexander Bublik (first round)
6. Marin Čilić (final)
7. Ilya Ivashka (withdrew)
8. Laslo Đere (first round)

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
	LL	Ričardas Berankis	3	4
	6	Marin Čilić	6	6
								6	Marin Čilić	2	4
								2	Aslan Karatsev	6	6
	3	Karen Khachanov	67	1
	2	Aslan Karatsev	79	6

Top half

	First round							Second round							Quarterfinals							Semifinals
								1	A Rublev	7	64	3
	WC	R Safiullin	6	66	4				A Mannarino	5	77	6
		A Mannarino	1	78	6											A Mannarino	2	61
		F Coria	6	5	6										LL	R Berankis	6	77
	WC	A Kachmazov	2	7	2				F Coria	2	1
	WC	E Donskoy	1	3				LL	R Berankis	6	6
	LL	R Berankis	6	6																		LL	R Berankis	3	4
																						6	M Čilić	6	6
								4	F Krajinović	3	4
	PR	G Pella	2	0r					P Martínez	6	6
		P Martínez	6	0												P Martínez	1	2
		T Paul	79	7											6	M Čilić	6	6
		M Ymer	67	5					T Paul	5	3
	Q	D Džumhur	77	1	1			6	M Čilić	7	6
	6	M Čilić	64	6	6

Bottom half

	First round							Second round							Quarterfinals							Semifinals
	5	A Bublik	4	3
	Q	I Marchenko	6	6				Q	I Marchenko	1	7	4
		J Millman	65	6	6				J Millman	6	5	6
		B Bonzi	77	4	3											J Millman	5	64
		J Duckworth	3	7	6										3	K Khachanov	7	77
	Q	B Gojo	6	5	2				J Duckworth	6	3	1
								3	K Khachanov	3	6	6
																						3	K Khachanov	67	1
	8	L Đere	77	5	3																	2	A Karatsev	79	6
	PR	G Simon	63	7	6			PR	G Simon	6	6
		M McDonald	6	6					M McDonald	3	2
		Y Nishioka	3	4											PR	G Simon	4	3
		M Kecmanović	3	6	4										2	A Karatsev	6	6
	Q	E Gerasimov	6	1	6			Q	E Gerasimov	4	3
								2	A Karatsev	6	6

Qualifying

Seeds

1. Egor Gerasimov (qualified)
2. Ričardas Berankis (qualifying competition, lucky loser)
3. Radu Albot (first round)
4. Damir Džumhur (qualified)
5. Jurij Rodionov (qualifying competition)
6. Zdeněk Kolář (qualifying competition)
7. Marc Polmans (first round)
8. Elias Ymer (qualifying competition)

Qualifiers

1. Egor Gerasimov
2. Borna Gojo
3. Illya Marchenko
4. Damir Džumhur

Lucky loser

1. Ričardas Berankis

Qualifying draw

First qualifier

	First round							Qualifying competition
	1	Egor Gerasimov	6	6
		Ramkumar Ramanathan	3	4
								1	Egor Gerasimov	6	1	6
								8	Elias Ymer	4	6	2
	Alt	Pavel Kotov	2	3
	8	Elias Ymer	6	6

Second qualifier

	First round							Qualifying competition
	2	Ričardas Berankis	6	6
		Dmitry Popko	4	1
								2	Ričardas Berankis	6	5	4
									Borna Gojo	4	7	6
		Borna Gojo	77	6
	7	Marc Polmans	65	2

Third qualifier

	First round							Qualifying competition
	3	Radu Albot	65	3
		Illya Marchenko	77	6
									Illya Marchenko	6	6
								5	Jurij Rodionov	4	1
	PR	Denis Istomin	4	2
	5	Jurij Rodionov	6	6

Fourth qualifier

	First round							Qualifying competition
	4	Damir Džumhur	69	6	6
	WC	Maxim Zhukov	711	0	4
								4	Damir Džumhur	7	6
								6	Zdeněk Kolář	5	3
	WC	Yaroslav Demin	4	2
	6	Zdeněk Kolář	6	6

External links

• Main draw
• Qualifying draw