# 2023 Nonthaburi Challenger – Singles

Stuart Parker was the defending champion but lost in the qualifying competition to Giovanni Fonio.
Dennis Novak won the title after defeating Wu Tung-lin 6–4, 6–4 in the final.

## Seeds

* Fábián Marozsán (second round)
* Dennis Novak (champion)
* Wu Tung-lin (final)
* Antoine Escoffier (semifinals)
* Gianluca Mager (first round)
* Paul Jubb (first round)
* Max Purcell (quarterfinals)
* Hsu Yu-hsiou (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 |
| | Lloyd Harris | 4 | 5 | | | | |
| 3 | Wu Tung-lin | 6 | 7 | | | | |
| 3 | Wu Tung-lin | 6 | 7 | 3 | Wu Tung-lin | 4 | 4 |
| | | | | 2 | Dennis Novak | 6 | 6 |
| 4 | Antoine Escoffier | 3 | 2 | 2 | Dennis Novak | 6 | 6 |
| 2 | Dennis Novak | 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 |
| 1 | F Marozsán | 6 | 6 | | | | | | | | | | | | | | | |
| WC | P Kovapitukted | 3 | 3 | | 1 | F Marozsán | 6 | 0 | 3 | | | | | | | | | |
| | B Hassan | 2 | 5 | | | L Harris | 3 | 6 | 6 | | | | | | | | | |
| | L Harris | 6 | 7 | | | | | | | | L Harris | 6$^7$ | 6 | 6 | | | | |
| | M Trungelliti | 5 | 2 | | | | | | | 8 | Y-h Hsu | 7$^9$ | 3 | 4 | | | | |
| Q | D Kelly | 7 | 6 | | Q | D Kelly | 2 | 2 | | | | | | | | | | |
| | H Moriya | 3 | 2 | | 8 | Y-h Hsu | 6 | 6 | | | | | | | | | | |
| 8 | Y-h Hsu | 6 | 6 | | | | | | | | | | | | | L Harris | 4 | 5 |
| 3 | T-l Wu | 6 | 6 | | | | | | | | | | | | 3 | T-l Wu | 6 | 7 |
| WC | T Suksumrarn | 4 | 1 | | 3 | T-l Wu | 6$^4$ | 7 | 6 | | | | | | | | | |
| | Y Uchiyama | 6 | 6 | | | Y Uchiyama | 7$^7$ | 5 | 4 | | | | | | | | | |
| WC | Maximus Jones | 4 | 4 | | | | | | | 3 | T-l Wu | 7 | 3 | 6 | | | | |
| | V Royer | 4 | 6 | 2 | | | | | | Q | E Donskoy | 5 | 6 | 3 | | | | |
| Q | Alafia Ayeni | 6 | 3 | 6 | Q | A Ayeni | 4 | 4 | | | | | | | | | | |
| Q | E Donskoy | 6 | 7$^7$ | | Q | E Donskoy | 6 | 6 | | | | | | | | | | |
| 6 | P Jubb | 1 | 6$^5$ | | | | | | | | | | | | | | | |

### 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 |
| 7 | M Purcell | 6 | 6 | | | | | | | | | | | | | | | |
| | S Travaglia | 2 | 4 | | 7 | M Purcell | 7$^7$ | 6 | | | | | | | | | | |
| | M Moraing | 7 | 6$^5$ | 6 | | M Moraing | 6$^5$ | 4 | | | | | | | | | | |
| Q | L Pouille | 5 | 7$^7$ | 3 | | | | | | 7 | M Purcell | 2 | 6$^8$ | | | | | |
| | S Shimabukuro | 6 | 3 | 6 | | | | | | 4 | A Escoffier | 6 | 7$^{10}$ | | | | | |
| | B Zhukayev | 4 | 6 | 4 | | S Shimabukuro | 6 | 6$^6$ | 3 | | | | | | | | | |
| | S Mochizuki | 4 | 7$^7$ | 2 | 4 | A Escoffier | 2 | 7$^8$ | 6 | | | | | | | | | |
| 4 | A Escoffier | 6 | 6$^5$ | 6 | | | | | | | | | | | 4 | A Escoffier | 3 | 2 |
| 5 | G Mager | 3 | 7$^8$ | 3 | | | | | | | | | | | 2 | D Novak | 6 | 6 |
| Q | H Squire | 6 | 6$^6$ | 6 | Q | H Squire | 4 | 3 | | | | | | | | | | |
| | M Gengel | 6 | 6$^4$ | 6 | | M Gengel | 6 | 6 | | | | | | | | | | |
| | T Sandgren | 4 | 7$^7$ | 1 | | | | | | | M Gengel | 3 | 7$^7$ | 3 | | | | |
| Q | G Fonio | 5 | 7$^7$ | 7$^9$ | | | | | | 2 | D Novak | 6 | 6$^5$ | 6 | | | | |
| | TA Tirante | 7 | 6$^3$ | 6$^7$ | Q | G Fonio | 2 | 1 | | | | | | | | | | |
| | D Added | 2 | 2 | | 2 | D Novak | 6 | 6 | | | | | | | | | | |
| 2 | D Novak | 6 | 6 | | | | | | | | | | | | | | | |