Singles
1973 South American Open
Final
Champion	Guillermo Vilas
Runner-up	Björn Borg
Score	3–6, 6–7, 6–4, 6–6 ret.
Details
Draw	32
Events
Singles Doubles
← 1972 · South American Open · 1974 →

Guillermo Vilas defeated Björn Borg 3–6, 6–7, 6–4, 6–6 after Borg retired to win the 1973 ATP Buenos Aires singles competition. Karl Meiler was the champion but did not defend his title.

• NB: All rounds up to but not including the semifinals were the best of 3 sets. The semifinals and final were the best of 5 sets.

	Final
		Björn Borg	6	7	4	6	R
		Guillermo Vilas	3	6	6	6

	First round									Second round									Quarterfinals									Semifinals
		B Borg	6	6
		R Caviglia	0	2							B Borg	6	7
		R Cano	6	6							R Cano	4	6
		A Cornejo	3	4																B Borg	6	3	6
		I Țiriac	6	6																I Țiriac	1	6	3
		H Romani	4	0							I Țiriac	6	6
		P Cornejo	6	6							P Cornejo	1	4
		V Pecci	2	3																									B Borg	6	6	6
		I Molina	6	6																									I Molina	2	3	2
		N Kalogeropoulos	1	3							I Molina	7	6
		J Ganzábal	7	6							J Ganzábal	6	0
		A Pierola	6	3																I Molina	6	2	6
		Z Franulović	6	6																Z Franulović	4	6	3
		C Gattiker	2	1							Z Franulović	6	6
		T Koch	6	6							T Koch	4	2
		F Dalla Fontana	1	2

	First round									Second round									Quarterfinals									Semifinals
		F Mastelli	6	2	4
		J-B Chanfreau	4	6	6						J-B Chanfreau	1	6	2
		T Lynch	2	2							T Ovici	6	0	6
		T Ovici	6	6																T Ovici	4	3
		E Zuleta	2	0																G Vilas	6	6
		H Kary	6	6							H Kary	2	1
		R Gratz	5	6							G Vilas	6	6
		G Vilas	7	7																									G Vilas	6	6	7
		H Varela	2	7	1																								E Dibbs	4	1	6
		J Pinto-Bravo	6	6	6						J Pinto-Bravo	6	6
		J Rivera	2	3							K Johansson	3	2
		K Johansson	6	6																J Pinto-Bravo	1	2
		L Soriano	1	0																E Dibbs	6	6
		E Mandarino	6	6							E Mandarino	3	4
		T Quintin	2	3							E Dibbs	6	6
		E Dibbs	6	6

• ATP Singles draw