Luiz Mattar won in the final 6–4, 5–7, 6–4 against Martín Jaite.

A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated.

	First round							Second round							Quarterfinals							Semifinals							Final
	1	L Mattar	6	3	3
	WC	J Oncins	1	6	0/r			1	L Mattar	6	6
		P Doohan	6	4	6				P Doohan	3	1
	Q	J Sobel	1	6	4										1	L Mattar	6	6
		F Yunis	4	5												T Högstedt	4	4
		T Högstedt	6	7					T Högstedt	7	6
	Q	R Jabali	6	1	7			Q	R Jabali	5	3
	8	T Wilkison	3	6	6																	1	L Mattar	6	6
	4	E Bengoechea	6	6																		5	C Motta	4	3
		M Menezes	2	2				4	E Bengoechea	6	6
		P Rebolledo	6	6					P Rebolledo	2	2
		R Acuña	2	3											4	E Bengoechea	7	4	4
		M Ingaramo	6	1											5	C Motta	5	6	6
		I Kley	7	6					I Kley	2	4
	WC	A Hocevar	2	7	2			5	C Motta	6	6
	5	C Motta	6	5	6																								1	Luiz Mattar	6	5	6
	6	J Frana	5	5																									3	Martín Jaite	4	7	4
	WC	M Hennemann	7	7				WC	M Hennemann	3	4
		D Marcelino	6	6	4				G Rivas	6	6
		G Rivas	3	7	6											G Rivas	1	3
		R Argüello	6	6	3										3	M Jaite	6	6
		F Roese	1	7	6				F Roese	4	4
		K Kinnear	7	5	5			3	M Jaite	6	6
	3	M Jaite	6	7	7																	3	M Jaite	4	6	6
	7	T Witsken	7	4	7																	7	T Witsken	6	4	4
		D Cassidy	5	6	5			7	T Witsken	6	6
	Q	C Kist	3	4					C Mezzadri	4	3
		C Mezzadri	6	6											7	T Witsken	7	6
		P Baur	6	6											2	H de la Peña	6	1
		J Lozano	3	4					P Baur	2	6
	Q	F Pinto	4	0				2	H de la Peña	6	7
	2	H de la Peña	6	6

• 1989 Rio de Janeiro Open draw