Ken Kuperstein defeated Stefan Heckmanns 6-4 6-4 in the USA 2 Masters 2 round of 64 on hard.
Kuperstein K. took it in straight sets.
Ken Kuperstein beat Stefan Heckmanns 6-4 6-4. Umpiry, "Ken Kuperstein vs Stefan Heckmanns — USA 2 Masters 2 Round of 64", https://umpiry.com/match/1991-04-29/heckmanns-vs-kuperstein-usa-2-masters-2-r64?utm_source=cite (as of 29 April 1991).