The 1973 Louisville Open, also known as the First National Tennis Classic, was a men's tennis tournament played on outdoor clay courts at the Louisville Tennis Center in Louisville, Kentucky, USA. It was the fourth edition of the tournament and was held from 30 July through 5 August 1973. The tournament was part of the Grand Prix tennis circuit and categorized in Group A. The singles final was won by fourth-seeded Manuel Orantes who earned 80 Grand Prix points.[1] [2]
Manuel Orantes defeated 
John Newcombe 3–6, 6–3, 6–4
Manuel Orantes / Ion Țiriac defeated 
Clark Graebner / John Newcombe 0–6, 6–4, 6–3