# 2018 Marburg Open – Singles

Filip Krajinović was the defending champion but chose not to defend his title.
Juan Ignacio Londero won the title after defeating Hugo Dellien 3–6, 7–5, 6–4 in the final.

## Seeds

* Jürgen Zopp (second round)
* Yannick Hanfmann (first round)
* Hugo Dellien (final)
* Thiago Monteiro (second round)
* Pedro Sousa (second round)
* Rogério Dutra Silva (first round)
* Alexey Vatutin (second round)
* Henri Laaksonen (second 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 | Semifinals | Final | Final | Final | Final | Final |
| | Juan Ignacio Londero | 7 | 1 | 6 | | | | | |
| | Félix Auger-Aliassime | 5 | 6 | 1 | | | | | |
| | Félix Auger-Aliassime | 5 | 6 | 1 | | Juan Ignacio Londero | 3 | 7 | 6 |
| | | | | | 3 | Hugo Dellien | 6 | 5 | 4 |
| 3 | Hugo Dellien | 6 | 6 | | 3 | Hugo Dellien | 6 | 5 | 4 |
| WC | Julian Lenz | 3 | 3 | | | | | | |

### 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 | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | J Zopp | 6 | 6 | | | | | | | | | | | | | |
| | D Gimeno Traver | 4 | 1 | | 1 | J Zopp | 4 | 2 | | | | | | | | |
| | D Brown | 3 | 4 | | | JI Londero | 6 | 6 | | | | | | | | |
| | JI Londero | 6 | 6 | | | | | | | JI Londero | 6 | 6 | | | | |
| | C Berlocq | 6 | 6 | | | | | | | C Berlocq | 1 | 4 | | | | |
| | M Moraing | 4 | 2 | | | C Berlocq | 6 | 4 | 7 | | | | | | | |
| WC | M Rosenkranz | 5 | 4 | | 7 | A Vatutin | 3 | 6 | 5 | | | | | | | |
| 7 | A Vatutin | 7 | 6 | | | | | | | | | | JI Londero | 7 | 1 | 6 |
| 4 | T Monteiro | 3 | 6 | 6 | | | | | | | | | F Auger-Aliassime | 5 | 6 | 1 |
| SE | G Mager | 6 | 2 | 2 | 4 | T Monteiro | 3 | 6 | 3 | | | | | | | |
| | O Otte | 6 | 6 | | | O Otte | 6 | 1 | 6 | | | | | | | |
| WC | B Hassan | 0 | 4 | | | | | | | O Otte | 4 | 5 | | | | |
| | F Auger-Aliassime | 6 | 4 | 6 | | | | | | F Auger-Aliassime | 6 | 7 | | | | |
| Q | D Dima | 3 | 6 | 4 | | F Auger-Aliassime | 6 | 7$^7$ | | | | | | | | |
| | C Lestienne | 4 | 7$^7$ | 3 | 8 | H Laaksonen | 3 | 6$^5$ | | | | | | | | |
| 8 | H Laaksonen | 6 | 6$^2$ | 6 | | | | | | | | | | | | |

### 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 | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | P Sousa | 6 | 6 | | | | | | | | | | | | | | |
| | N Serdarušić | 4 | 1 | | 5 | P Sousa | 6$^5$ | 6 | 3 | | | | | | | | |
| | M Polmans | 3 | 3 | | | A Martin | 7$^7$ | 3 | 6 | | | | | | | | |
| | A Martin | 6 | 6 | | | | | | | | A Martin | 2 | 1 | | | | |
| Q | T Bellucci | 6$^8$ | 6 | 6 | | | | | | 3 | H Dellien | 6 | 6 | | | | |
| | L Harris | 7$^{10}$ | 4 | 4 | Q | T Bellucci | 6 | 3 | 6$^6$ | | | | | | | | |
| Q | T Lamasine | 2 | 2 | | 3 | H Dellien | 3 | 6 | 7$^8$ | | | | | | | | |
| 3 | H Dellien | 6 | 6 | | | | | | | | | | | 3 | H Dellien | 6 | 6 |
| 6 | R Dutra Silva | 4 | 4 | | | | | | | | | | | WC | J Lenz | 3 | 3 |
| | G Sakharov | 6 | 6 | | | G Sakharov | 3 | 0 | | | | | | | | | |
| Q | E Benchetrit | 6 | 6 | | Q | E Benchetrit | 6 | 6 | | | | | | | | | |
| | R Ojeda Lara | 4 | 4 | | | | | | | Q | E Benchetrit | 4 | 5 | | | | |
| | S Ofner | 1 | 6$^4$ | | | | | | | WC | J Lenz | 6 | 7 | | | | |
| WC | J Lenz | 6 | 7$^7$ | | WC | J Lenz | 3 | 6 | 7$^7$ | | | | | | | | |
| WC | R Molleker | 4 | 7$^7$ | 6 | WC | R Molleker | 6 | 3 | 6$^2$ | | | | | | | | |
| 2 | Y Hanfmann | 6 | 6$^4$ | 4 | | | | | | | | | | | | | |