| Defchamp: | Steffi Graf |
| Champ: | Steffi Graf |
| Runner: |  Sabatini |
| Score: | 6–3, 6–1 |
| Draw: | 56 |
| Seeds: | 16 |
| Type: | singles doubles |
| Before Name: | WTA German Open – Singles |
| After Name: | Lufthansa Cup German Open – Singles |
| Main Name: | German Open (WTA) WTA German Open |
Steffi Graf was the defending champion going into the final against her rival Gabriela Sabatini. Just the previous month, Sabatini defeated Steffi Graf 3–6, 6–3, 7–5 in the final at Amelia Island, Florida. Now, in her native Germany, Steffi would turn the tables against Sabatini, beating her 6–3, 6–1. Prior to this match, Sabatini had played in four finals in 1989, with her winning twice. For Steffi, this victory was her seventh of the year, and marked the sixteenth time out of nineteen matches she had beaten Sabatini.
A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated. The top eight seeds received a bye to the second round.
Gabriela Sabatini (final)
Mary Joe Fernández (third round)
Helen Kelesi (semifinals)
Sandra Cecchini (quarterfinals)
Barbara Paulus (quarterfinals) Bettina Fulco (second round)
Nathalie Tauziat (third round) Terry Phelps (first round)
Nicole Provis (first round) Isabelle Demongeot (first round) Gretchen Magers (first round)