# 1989 Monte Carlo Open – Singles

Alberto Mancini won in the final 7–5, 2–6, 7–6, 7–5 against Boris Becker.
Ivan Lendl was the defending champion but did not compete this year.

## Seeds

A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated. All sixteen seeds received a bye to the second round.
* Mats Wilander (semifinals)
* Boris Becker (final)
* Kent Carlsson (withdrew)
* Jakob Hlasek (second round)
* Jimmy Connors (second round)
* Henri Leconte (second round, retired)
* Emilio Sánchez (second round)
* Guillermo Pérez Roldán (quarterfinals)
* Jonas Svensson (third round)
* Ronald Agénor (quarterfinals)
* Slobodan Živojinović (second round)
* Andrei Chesnokov (second round)
* Horst Skoff (semifinals)
* Alberto Mancini (champion)
* Mark Woodforde (second round)
* Jordi Arrese (third round)

## 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 | Final |
| 1 | Mats Wilander | 0 | 3 | | | | | | |
| 14 | Alberto Mancini | 6 | 6 | | | | | | |
| 14 | Alberto Mancini | 6 | 6 | 14 | Alberto Mancini | 7 | 2 | 7 | 7 |
| | | | | 2 | Boris Becker | 5 | 6 | 6 | 5 |
| 13 | Horst Skoff | 3 | 3 | 2 | Boris Becker | 5 | 6 | 6 | 5 |
| 2 | Boris Becker | 6 | 6 | | | | | | |

### Top half
#### Section 1

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 1 | M Wilander | 7 | 6 | | | | | | | | | |
| WC | D Nargiso | 6 | 7 | | WC | D Nargiso | 6 | 1 | | | | | | | | | |
| | F Luna | 4 | 6 | | | | | | | 1 | M Wilander | 6 | 6 | | | | |
| | E Jelen | 3 | 2 | | | | | | | | M Filippini | 4 | 4 | | | | |
| | M Filippini | 6 | 6 | | | M Filippini | 7 | 6 | | | | | | | | | |
| | | | | | 15 | M Woodforde | 5 | 1 | | | | | | | | | |
| | | | | | | | | | | | | | | 1 | M Wilander | 6 | 7 |
| | | | | | | | | | | | | | | 9 | R Agénor | 3 | 6 |
| | | | | | 10 | R Agénor | 6 | 2 | 6 | | | | | | | | |
| Q | P Arraya | 2 | 6 | 6 | Q | R Osterthun | 2 | 6 | 2 | | | | | | | | |
| Q | R Osterthun | 6 | 2 | 7 | | | | | | 9 | R Agénor | 6 | 7 | | | | |
| | L Lavalle | 0 | 1 | | | | | | | | G Forget | 2 | 5 | | | | |
| | G Forget | 6 | 6 | | | G Forget | 6 | 6 | 6 | | | | | | | | |
| | | | | | 7 | E Sánchez | 7 | 4 | 1 | | | | | | | | |

#### Section 2

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | LL | J Nyström | 1 | 1 | | | | | | | | |
| SE | G Ivanišević | 5 | 4 | | Q | C Limberger | 6 | 6 | | | | | | | | |
| Q | C Limberger | 7 | 6 | | | | | | Q | C Limberger | 1 | 3 | | | | |
| Q | F Santoro | 4 | 1 | | | | | | 14 | A Mancini | 6 | 6 | | | | |
| SE | F Cancellotti | 6 | 6 | | SE | F Cancellotti | 4 | 4 | | | | | | | | |
| | | | | | 14 | A Mancini | 6 | 6 | | | | | | | | |
| | | | | | | | | | | | | | 14 | A Mancini | 6 | 6 |
| | | | | | | | | | | | | | WC | C-U Steeb | 3 | 3 |
| | | | | | 12 | A Chesnokov | 4 | 4 | | | | | | | | |
| | K Nováček | 2 | 1 | | WC | C-U Steeb | 6 | 6 | | | | | | | | |
| WC | C-U Steeb | 6 | 6 | | | | | | WC | C-U Steeb | 6 | 6 | | | | |
| | P Canè | 2 | 7 | 6 | | | | | | P Canè | 4 | 1 | | | | |
| | J Sánchez | 6 | 6 | 0 | | P Canè | 7 | 6 | | | | | | | | |
| | | | | | 5 | J Connors | 6 | 1 | | | | | | | | |

### Bottom half
#### Section 3

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 6 | H Leconte | 3 | 2$^r$ | | | | | | | | | |
| | H de la Peña | 6 | 4 | 6 | | P Kühnen | 6 | 3 | | | | | | | | | |
| | P Kühnen | 3 | 6 | 7 | | | | | | | P Kühnen | 5 | 2 | | | | |
| | J Gunnarsson | 7 | 6 | | | | | | | | J Gunnarsson | 7 | 6 | | | | |
| | C Bergström | 5 | 1 | | | J Gunnarsson | 6 | 6 | | | | | | | | | |
| | | | | | 11 | S Živojinović | 4 | 2 | | | | | | | | | |
| | | | | | | | | | | | | | | | J Gunnarsson | 4 | 4 |
| | | | | | | | | | | | | | | 13 | H Skoff | 6 | 6 |
| | | | | | 13 | H Skoff | 4 | 6 | 6 | | | | | | | | |
| | O Delaître | 4 | 0 | | Q | M Střelba | 6 | 4 | 1 | | | | | | | | |
| Q | M Střelba | 6 | 6 | | | | | | | 13 | H Skoff | 7 | 7 | | | | |
| | M Jaite | 6 | 6 | 7 | | | | | | | M Jaite | 5 | 6 | | | | |
| | J Arias | 7 | 3 | 5 | | M Jaite | 6 | 6 | | | | | | | | | |
| | | | | | 4 | J Hlasek | 4 | 1 | | | | | | | | | |

#### Section 4

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 8 | G Pérez Roldán | 6 | 6 | | | | | | | | | |
| WC | T Champion | 6 | 2 | 6 | | M Gustafsson | 4 | 2 | | | | | | | | | |
| | M Gustafsson | 2 | 6 | 7 | | | | | | 8 | G Pérez Roldán | 6 | 6 | | | | |
| | M Vajda | 3 | 1 | | | | | | | 9 | J Svensson | 4 | 4 | | | | |
| | T Tulasne | 6 | 6 | | | T Tulasne | 7 | 3 | 5 | | | | | | | | |
| | | | | | 9 | J Svensson | 6 | 6 | 7 | | | | | | | | |
| | | | | | | | | | | | | | | 8 | G Pérez Roldán | 3 | 3 |
| | | | | | | | | | | | | | | 2 | B Becker | 6 | 6 |
| | | | | | 16 | J Arrese | 6 | 6 | | | | | | | | | |
| | J Frawley | 6 | 6 | | | J Frawley | 1 | 0 | | | | | | | | | |
| Q | L Jönsson | 0 | 3 | | | | | | | 16 | J Arrese | 1 | 3 | | | | |
| WC | H Sundström | 4 | 6 | | | | | | | 2 | B Becker | 6 | 6 | | | | |
| | L Duncan | 6 | 7 | | | L Duncan | 4 | 1 | | | | | | | | | |
| | | | | | 2 | B Becker | 6 | 6 | | | | | | | | | |