2021 Belgrade Open – Singles

This was the first edition of the tournament, primarily created due to the one-week delay of the 2021 French Open.^[1]

Singles
2021 Belgrade Open
Champion	Novak Djokovic
Runner-up	Alex Molčan
Score	6–4, 6–3

Main article: 2021 Belgrade Open

Novak Djokovic won the title, defeating Alex Molčan in the final, 6–4, 6–3.^[2] It was Djokovic's third title ever in a tournament held in Serbia (excluding the Davis Cup).

Seeds

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

1. Novak Djokovic (champion)
2. Gaël Monfils (second round)
3. Nikoloz Basilashvili (second round)
4. Adrian Mannarino (second round)
5. Dušan Lajović (quarterfinals)
6. Filip Krajinović (withdrew)
7. Miomir Kecmanović (first round)
8. Federico Delbonis (semifinals)

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
	1	Novak Djokovic	6	4	6
	Q	Andrej Martin	1	6	0
								1	Novak Djokovic	6	6
								Q	Alex Molčan	4	3
	Q	Alex Molčan	4	6	6
	8	Federico Delbonis	6	4	4

Top half

	First round							Second round							Quarterfinals							Semifinals
								1	N Djokovic	6	77
	LL	M Moraing	4	79	7			LL	M Moraing	2	64
		E Gerasimov	6	67	5										1	N Djokovic	6	6
	WC	M Topo	6	2	0										Alt	F Coria	1	0
	Alt	F Coria	4	6	6			Alt	F Coria	6	6
		P Cuevas	6	6					P Cuevas	3	2
	7	M Kecmanović	3	2																		1	N Djokovic	6	4	6
																						Q	A Martin	1	6	0
								3	N Basilashvili	1	6	64
	Q	C O'Connell	6	67	5			Q	A Martin	6	4	77
	Q	A Martin	3	79	7										Q	A Martin	3	6	6
		T Sandgren	4	2											5	D Lajović	6	3	4
		J Chardy	6	6					J Chardy	3	4
		R Berankis	3	3				5	D Lajović	6	6
	5	D Lajović	6	6

Bottom half

	First round							Second round							Quarterfinals							Semifinals
	Q	A Molčan	6	6
	WC	H Međedović	4	3				Q	A Molčan	6	6
	WC	P Krstin	6	3	6			WC	P Krstin	0	0
		S-w Kwon	2	6	1										Q	A Molčan	6	6
		L Pouille	5	2												F Verdasco	2	0
		F Verdasco	7	6					F Verdasco	77	6
								4	A Mannarino	64	0
																						Q	A Molčan	4	6	6
	8	F Delbonis	3	6	6																	8	F Delbonis	6	4	4
	LL	L Klein	6	3	4			8	F Delbonis	78	3	6
		R Albot	2	2					T Monteiro	66	6	4
		T Monteiro	6	6											8	F Delbonis	w/o
	SE	A Rinderknech	0	4											Q	R Carballés Baena
	Q	R Carballés Baena	6	6				Q	R Carballés Baena	6	3	77
								2	G Monfils	1	6	64

Qualifying

Seeds

1. Federico Coria (moved to main draw)
2. Roberto Carballés Baena (qualified)
3. Andrej Martin (qualified)
4. Christopher O'Connell (qualified)
5. Mats Moraing (qualifying competition, lucky loser)
6. Lukáš Klein (qualifying competition, lucky loser)
7. Vít Kopřiva (qualifying competition)
8. Alex Molčan (qualified)

Qualifiers

1. Alex Molčan
2. Roberto Carballés Baena
3. Andrej Martin
4. Christopher O'Connell

Lucky losers

1. Mats Moraing
2. Lukáš Klein

Qualifying draw

First qualifier

	First round							Qualifying competition
	Alt	John-Patrick Smith	4	65
	WC	Carlos Gómez-Herrera	6	77
								WC	Carlos Gómez-Herrera	3	68
								8	Alex Molčan	6	710
	Alt	Nerman Fatić	4	1
	8	Alex Molčan	6	6

Second qualifier

	First round							Qualifying competition
	2	Roberto Carballés Baena	6	6
		Mirza Bašić	2	3
								2	Roberto Carballés Baena	6	6
								7	Vít Kopřiva	4	4
		Alexey Vatutin	3	6	4
	7	Vít Kopřiva	6	3	6

Third qualifier

	First round							Qualifying competition
	3	Andrej Martin	6	6
		Akira Santillan	3	3
								3	Andrej Martin	6	6
								5	Mats Moraing	1	3
		Malek Jaziri	3	4
	5	Mats Moraing	6	6

Fourth qualifier

	First round							Qualifying competition
	4	Christopher O'Connell	6	6
		Darian King	1	3
								4	Christopher O'Connell	79	7
								6	Lukáš Klein	67	5
	WC	Marko Tepavac	4	1
	6	Lukáš Klein	6	6