# 2018 AON Open Challenger – Singles

Stefanos Tsitsipas was the defending champion but chose not to defend his title.
Lorenzo Sonego won the title after defeating Dustin Brown 6–2, 6–1 in the final.

## Seeds

* Benoît Paire (withdrew)
* Martin Kližan (second round, retired)
* Paolo Lorenzi (second round)
* Hubert Hurkacz (quarterfinals)
* Federico Delbonis (semifinals)
* Guido Andreozzi (first round)
* Thiago Monteiro (first round)
* Lorenzo Sonego (champion)

## 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 |
| 5 | Federico Delbonis | 5 | 3 | | | | |
| 8 | Lorenzo Sonego | 7 | 6 | | | | |
| 8 | Lorenzo Sonego | 7 | 6 | 8 | Lorenzo Sonego | 6 | 6 |
| | | | | WC | Dustin Brown | 2 | 1 |
| WC | Dustin Brown | 6 | 7$^8$ | WC | Dustin Brown | 2 | 1 |
| LL | Thomaz Bellucci | 3 | 6$^6$ | | | | |

### 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| LL | JP Varillas | 6 | 5 | 3 | | | | | | | | | | | | | | |
| | S Travaglia | 4 | 7 | 6 | | S Travaglia | 6 | 6 | | | | | | | | | | |
| | G Quinzi | 6 | 4 | 3 | | V Galović | 4 | 4 | | | | | | | | | | |
| | V Galović | 4 | 6 | 6 | | | | | | | S Travaglia | 3 | 6 | 6$^1$ | | | | |
| WC | G Fonio | 6 | 6 | | | | | | | 5 | F Delbonis | 6 | 3 | 7$^7$ | | | | |
| | G Elias | 4 | 2 | | WC | G Fonio | 1 | 3 | | | | | | | | | | |
| | R Dutra Silva | 6 | 4 | 3 | 5 | F Delbonis | 6 | 6 | | | | | | | | | | |
| 5 | F Delbonis | 4 | 6 | 6 | | | | | | | | | | | 5 | F Delbonis | 5 | 3 |
| 4 | H Hurkacz | 6 | 1 | 6 | | | | | | | | | | | 8 | L Sonego | 7 | 6 |
| | A Arnaboldi | 3 | 6 | 2 | 4 | H Hurkacz | 5 | 7 | 6 | | | | | | | | | |
| Q | Z Piros | 4 | 1$^r$ | | | JI Londero | 7 | 5 | 0 | | | | | | | | | |
| | JI Londero | 6 | 4 | | | | | | | 4 | H Hurkacz | 6 | 3 | 6$^1$ | | | | |
| Q | A Avidzba | 6 | 4 | 1 | | | | | | 8 | L Sonego | 1 | 6 | 7$^7$ | | | | |
| | A Vatutin | 1 | 6 | 6 | | A Vatutin | 4 | 6 | 5 | | | | | | | | | |
| | S Robert | 1 | 2 | | 8 | L Sonego | 6 | 4 | 7 | | | | | | | | | |
| 8 | L Sonego | 6 | 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | G Andreozzi | 5 | 6 | 0 | | | | | | | | | | | | | | |
| WC | A Basso | 7 | 4 | 6 | WC | A Basso | 2 | 7 | 2 | | | | | | | | | |
| WC | D Brown | 6 | 7 | | WC | D Brown | 6 | 5 | 6 | | | | | | | | | |
| | P Andújar | 4 | 5 | | | | | | | WC | D Brown | 3 | 6 | 7$^7$ | | | | |
| Q | A Pellegrino | 2 | 4 | | | | | | | Alt | L Rosol | 6 | 4 | 6$^5$ | | | | |
| Alt | L Rosol | 6 | 6 | | Alt | L Rosol | 7$^7$ | 6 | | | | | | | | | | |
| | S Caruso | 2 | 6 | 4 | 3 | P Lorenzi | 6$^4$ | 3 | | | | | | | | | | |
| 3 | P Lorenzi | 6 | 3 | 6 | | | | | | | | | | | WC | D Brown | 6 | 7$^8$ |
| 7 | T Monteiro | 3 | 4 | | | | | | | | | | | | LL | T Bellucci | 3 | 6$^6$ |
| | C Garín | 6 | 6 | | | C Garín | 3 | 6 | 6 | | | | | | | | | |
| | S Napolitano | 4 | 2 | | Q | S Nagal | 6 | 3 | 4 | | | | | | | | | |
| Q | S Nagal | 6 | 6 | | | | | | | | C Garín | 6$^5$ | 4 | | | | | |
| LL | T Bellucci | 7$^8$ | 6 | | | | | | | LL | T Bellucci | 7$^7$ | 6 | | | | | |
| | GM Moroni | 6$^6$ | 3 | | LL | T Bellucci | 3 | 7 | 4 | | | | | | | | | |
| WC | F Baldi | 0 | 2 | | 2 | M Kližan | 6 | 5 | 0$^r$ | | | | | | | | | |
| 2 | M Kližan | 6 | 6 | | | | | | | | | | | | | | | |