# 1991 Porsche Tennis Grand Prix – Singles

Mary Joe Fernández was the defending champion, but lost in the quarterfinals to Helena Suková.
16-year old Anke Huber won the title by defeating Martina Navratilova 2–6, 6–2, 7–6$^{(7–4)}$ in the final.

## Seeds

* Martina Navratilova (final)
* Mary Joe Fernández (quarterfinals)
* Conchita Martínez (first round)
* Jana Novotná (quarterfinals)
* Zina Garrison (quarterfinals)
* Leila Meskhi (second round)
* Helena Suková (semifinals)
* Nathalie Tauziat (quarterfinals)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final | Final |
| 1 | Martina Navratilova | 6 | 7$^7$ | | | | | |
| | Judith Wiesner | 2 | 6$^4$ | | | | | |
| | Judith Wiesner | 2 | 6$^4$ | 1 | Martina Navratilova | 6 | 2 | 6$^4$ |
| | | | | | Anke Huber | 2 | 6 | 7$^7$ |
| | Anke Huber | 6 | 7$^7$ | | Anke Huber | 2 | 6 | 7$^7$ |
| 7 | Helena Suková | 3 | 6$^2$ | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | M Navratilova | 6 | 6 | | | | | | | | | | | | | | |
| Q | M Babel | 4 | 2 | | 1 | M Navratilova | 6 | 7 | | | | | | | | | |
| | B Paulus | 6$^6$ | 3 | | | E Reinach | 4 | 5 | | | | | | | | | |
| | E Reinach | 7$^8$ | 6 | | | | | | | 1 | M Navratilova | 6 | 7 | | | | |
| | M Bollegraf | 6 | 7 | | | | | | | 8 | N Tauziat | 4 | 5 | | | | |
| | K Kschwendt | 3 | 5 | | | M Bollegraf | | | | | | | | | | | |
| | P Shriver | 7 | 3 | 1 | 8 | N Tauziat | w/o | | | | | | | | | | |
| 8 | N Tauziat | 5 | 6 | 6 | | | | | | | | | | 1 | M Navratilova | 6 | 7$^7$ |
| 4 | J Novotná | 6 | 6 | | | | | | | | | | | | J Wiesner | 2 | 6$^4$ |
| | K Oeljeklaus | 3 | 3 | | 4 | J Novotná | 6 | 6 | | | | | | | | | |
| | M Medvedeva | 3 | 6 | 6 | | M Medvedeva | 4 | 4 | | | | | | | | | |
| | H Kelesi | 6 | 4 | 4 | | | | | | 4 | J Novotná | 6$^7$ | 3 | | | | |
| | C Lindqvist | 2 | 2 | | | | | | | | J Wiesner | 7$^9$ | 6 | | | | |
| | J Wiesner | 6 | 6 | | | J Wiesner | 6 | 1 | 6 | | | | | | | | |
| | R McQuillan | 2 | 5 | | 6 | L Meskhi | 1 | 6 | 4 | | | | | | | | |
| 6 | L Meskhi | 6 | 7 | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | Z Garrison | 6 | 4 | 6 | | | | | | | | | | | | | | |
| Q | G Helgeson | 4 | 6 | 1 | 5 | Z Garrison | 6 | 4 | 6 | | | | | | | | | |
| | B Schultz | 6 | 7$^8$ | | | B Schultz | 3 | 6 | 2 | | | | | | | | | |
| LL | A Temesvári | 0 | 6$^6$ | | | | | | | 5 | Z Garrison | 2 | 1 | | | | | |
| | L McNeil | 4 | 1 | | | | | | | | A Huber | 6 | 6 | | | | | |
| | A Huber | 6 | 6 | | | A Huber | 6 | 6 | | | | | | | | | | |
| | N Zvereva | 7$^7$ | 7 | | | N Zvereva | 2 | 2 | | | | | | | | | | |
| 3 | C Martínez | 6$^1$ | 5 | | | | | | | | | | | | | A Huber | 6 | 7$^7$ |
| 7 | H Suková | 7$^7$ | 7$^7$ | | | | | | | | | | | | 7 | H Suková | 3 | 6$^2$ |
| Q | W Probst | 6$^3$ | 6$^2$ | | 7 | H Suková | 6$^2$ | 7 | 6 | | | | | | | | | |
| | A Frazier | 6 | 6 | | | A Frazier | 7$^7$ | 5 | 3 | | | | | | | | | |
| | E Pfaff | 2 | 1 | | | | | | | 7 | H Suková | 5 | 6 | 6 | | | | |
| | R Reggi-Concato | 1 | 2 | | | | | | | 2 | MJ Fernández | 7 | 3 | 3 | | | | |
| | R Zrubáková | 6 | 6 | | | R Zrubáková | 1 | 1 | | | | | | | | | | |
| Q | K Habšudová | 0 | 4 | | 2 | MJ Fernández | 6 | 6 | | | | | | | | | | |
| 2 | MJ Fernández | 6 | 6 | | | | | | | | | | | | | | | |