Singles
2021 Zagreb Open
Champion	Sebastián Báez
Runner-up	Juan Pablo Varillas
Score	3–6, 6–3, 6–1

This was the first edition of the tournament since 2011.^[1]

Sebastián Báez won the title after defeating Juan Pablo Varillas 3–6, 6–3, 6–1 in the final.

Seeds

Draw

Finals

	Semifinals							Final
		Juan Manuel Cerúndolo	1r
		Juan Pablo Varillas	5
									Juan Pablo Varillas	6	3	1
								Q	Sebastián Báez	3	6	6
	Q	Marcelo Tomás Barrios Vera	3	4
	Q	Sebastián Báez	6	6

Top half

	First round							Second round							Quarterfinals							Semifinals
	1	F Coria	6	79
		M Safwat	4	67				1	F Coria	64	2
		JM Cerúndolo	6	6					JM Cerúndolo	77	6
		E Donskoy	3	2												JM Cerúndolo	6	63	6
		B van de Zandschulp	6	3	7											B van de Zandschulp	4	77	2
		M Mmoh	4	6	5				B van de Zandschulp	6	2	6
		A Tabilo	6	6					A Tabilo	1	6	4
	6	B Bonzi	4	1																			JM Cerúndolo	1r
	4	Y Uchiyama	3	2																			JP Varillas	5
		N Milojević	6	6					N Milojević	77	6
		L Mayer	6	64	6				L Mayer	64	2
		F Ferreira Silva	3	77	3											N Milojević	63	3
	WC	Antun Vidak	0	1												JP Varillas	77	6
		B Rola	6	6					B Rola	4	2
		JP Varillas	77	7					JP Varillas	6	6
	5	P Sousa	64	5

Bottom half

	First round							Second round							Quarterfinals							Semifinals
	8	T Seyboth Wild	0	7	7
		R Safiullin	6	5	5			8	T Seyboth Wild	7	6
	Q	E Gulbis	65	65				WC	B Gojo	5	4
	WC	B Gojo	77	77											8	T Seyboth Wild	4	2
	Alt	D Popko	4	2											Q	MT Barrios Vera	6	6
	Q	MT Barrios Vera	6	6				Q	MT Barrios Vera	2	6	6
		J Jung	6	64	0r			3	A Martin	6	3	2
	3	A Martin	2	77	4																	Q	MT Barrios Vera	3	4
	7	D Džumhur	6	6																		Q	S Báez	6	6
		G Soeda	4	3				7	D Džumhur	77	1	5
	Q	S Báez	6	6				Q	S Báez	65	6	7
	Q	R Ramanathan	4	0											Q	S Báez	3	6	6
		K Żuk	4	6	6										2	P Martínez	6	3	4
		J Rodionov	6	3	3				K Żuk	66	2
	WC	N Serdarušić	4	77	3			2	P Martínez	78	6
	2	P Martínez	6	61	6

References

External links

• Main draw
• Qualifying draw