2023 Heilbronner Neckarcup – Singles

Daniel Altmaier was the defending champion^[1] but chose not to defend his title.

Singles
2023 Heilbronner Neckarcup
Champion	Matteo Arnaldi
Runner-up	Facundo Díaz Acosta
Score	7–6(7–4), 6–1

Main article: 2023 Heilbronner Neckarcup

Matteo Arnaldi won the title after defeating Facundo Díaz Acosta 7–6^(7–4), 6–1 in the final.^[2]

Seeds

1. Marco Cecchinato (first round)
2. Jaume Munar (quarterfinals)
3. Daniel Elahi Galán (quarterfinals)
4. Dominic Thiem (second round)
5. Matteo Arnaldi (champion)
6. Fábián Marozsán (second round)
7. Oscar Otte (first round)
8. Pavel Kotov (quarterfinals)

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
		Facundo Díaz Acosta	7	6
	WC	Rudolf Molleker	5	3
									Facundo Díaz Acosta	64	1
								5	Matteo Arnaldi	77	6
		Pedro Martínez	64	5
	5	Matteo Arnaldi	77	7

Top half

	First round							Second round							Quarterfinals							Semifinals
	1	M Cecchinato	5	3
	Q	A Santillan	7	6				Q	A Santillan	6	3	6
		J Kovalík	3	6	77				J Kovalík	2	6	3
		M Marterer	6	2	65										Q	A Santillan	5	3
	LL	M Janvier	6	6												F Díaz Acosta	7	6
	Q	Lucas Gerch	4	3				LL	M Janvier	1	6	65
		F Díaz Acosta	6	61	6				F Díaz Acosta	6	3	77
	7	O Otte	4	77	1																		F Díaz Acosta	7	6
	3	DE Galán	6	77																		WC	R Molleker	5	3
	Alt	C İlkel	4	63				3	DE Galán	5	6	6
	Q	J Kym	62	3					F Meligeni Alves	7	0	2
		F Meligeni Alves	77	6											3	DE Galán	4	7	5
	Q	S Fanselow	4	77	1										WC	R Molleker	6	5	7
	WC	R Molleker	6	65	6			WC	R Molleker	7	6
	Alt	H Casanova	3	4				6	F Marozsán	5	4
	6	F Marozsán	6	6

Bottom half

	First round							Second round							Quarterfinals							Semifinals
	8	P Kotov	78	6
		A Pellegrino	66	2				8	P Kotov	6	6
	Q	MH Rehberg	2	4r				Alt	D Added	2	2
	Alt	D Added	6	5											8	P Kotov	4	6	63
	Q	H Squire	4	2												P Martínez	6	4	77
		P Martínez	6	6					P Martínez	2	6	6
		K Uchida	4	4				4/WC	D Thiem	6	3	1
	4/WC	D Thiem	6	6																			P Martínez	64	5
	5	M Arnaldi	7	6																		5	M Arnaldi	77	7
		N Gombos	5	3				5	M Arnaldi	2	6	6
		O Krutykh	4	4				WC	M Topo	6	3	1
	WC	M Topo	6	6											5	M Arnaldi	1	6	7
		D Džumhur	5	1											2	J Munar	6	4	5
		T Skatov	7	6					T Skatov	2	5
		H Dellien	1	1				2	J Munar	6	7
	2	J Munar	6	6