# 2025 Nonthaburi Challenger II – Singles

Aslan Karatsev was the defending champion but lost in the second round to Marat Sharipov.
Rio Noguchi won the title after defeating Cui Jie 7–6$^{(11–9)}$, 6–2 in the final.

## Seeds

* Hsu Yu-hsiou (second round)
* Francesco Maestrelli (second round)
* Gonzalo Oliveira (withdrew)
* Bai Yan (first round)
* Marek Gengel (first round, retired)
* Sun Fajing (first round)
* Geoffrey Blancaneaux (first round)
* Rémy Bertola (first 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 |
| Rio Noguchi | 7 | 6$^4$ | 6 | | | |
| Murphy Cassone | 5 | 7$^7$ | 3 | | | |
| Murphy Cassone | 5 | 7$^7$ | 3 | Rio Noguchi | 7$^{11}$ | 6 |
| | | | | Cui Jie | 6$^9$ | 2 |
| Marat Sharipov | 6 | 3 | 6$^6$ | Cui Jie | 6$^9$ | 2 |
| Cui Jie | 3 | 6 | 7$^8$ | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | Y-h Hsu | 6 | 6 | | | | | | | | | | | | | | |
| Q | K Isomura | 2 | 1 | | 1 | Y-h Hsu | 2 | 1 | | | | | | | | | |
| WC | Maximus Jones | 6$^3$ | 6 | 6 | WC | M Jones | 6 | 6 | | | | | | | | | |
| Q | B Paire | 7$^7$ | 3 | 4 | | | | | WC | M Jones | 6 | 1 | 0 | | | | |
| WC | Thanapet Chanta | 5 | 3 | | | | | | | R Noguchi | 3 | 6 | 6 | | | | |
| | R Noguchi | 7 | 6 | | | R Noguchi | 6 | 6 | | | | | | | | | |
| | C Denolly | 7$^9$ | 4 | 6 | | C Denolly | 3 | 3 | | | | | | | | | |
| 6 | F Sun | 6$^7$ | 6 | 4 | | | | | | | | | | R Noguchi | 7 | 6$^4$ | 6 |
| LL | N Oberleitner | 4 | 6$^5$ | | | | | | | | | | | M Cassone | 5 | 7$^7$ | 3 |
| Q | J Paul | 6 | 7$^7$ | | Q | J Paul | 6 | 6 | | | | | | | | | |
| | E Dalla Valle | 6 | 6 | | | E Dalla Valle | 3 | 4 | | | | | | | | | |
| Q | Hikaru Shiraishi | 0 | 2 | | | | | | Q | J Paul | 6$^3$ | 6$^3$ | | | | | |
| | O Prihodko | 6 | 3 | 4 | | | | | | M Cassone | 7$^7$ | 7$^7$ | | | | | |
| | Andre Ilagan | 3 | 6 | 6 | | A Ilagan | 2 | 3 | | | | | | | | | |
| | M Cassone | 6 | 6 | | | M Cassone | 6 | 6 | | | | | | | | | |
| 8 | R Bertola | 4 | 1 | | | | | | | | | | | | | | |

### 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 | M Gengel | 1$^r$ | | | | | | | | | | | | | | | | |
| | H Moriya | 5 | | | | H Moriya | 4 | 4 | | | | | | | | | | |
| Q | Y Takahashi | 2 | 7$^8$ | 3 | Q | Y Takahashi | 6 | 6 | | | | | | | | | | |
| | M Imamura | 6 | 6$^6$ | 1$^r$ | | | | | | Q | Y Takahashi | 3 | 6 | 2 | | | | |
| | Marat Sharipov | 6 | 6 | | | | | | | | M Sharipov | 6 | 4 | 6 | | | | |
| Q | Z Kolář | 3 | 4 | | | M Sharipov | 7$^7$ | 5 | 6 | | | | | | | | | |
| | A Karatsev | 7 | 2 | 7$^7$ | | A Karatsev | 6$^2$ | 7 | 4 | | | | | | | | | |
| 4 | Y Bai | 5 | 6 | 6$^2$ | | | | | | | | | | | M Sharipov | 6 | 3 | 6$^6$ |
| 7 | G Blancaneaux | 0 | 4 | | | | | | | | | | | | J Cui | 3 | 6 | 7$^8$ |
| Alt | D Michalski | 6 | 6 | | Alt | D Michalski | 1 | 6 | 7$^7$ | | | | | | | | | |
| | J Sels | 7$^7$ | 6 | | | J Sels | 6 | 1 | 6$^1$ | | | | | | | | | |
| | C Tabur | 6$^4$ | 3 | | | | | | | Alt | D Michalski | 6 | 3 | 6$^4$ | | | | |
| WC | W Trongcharoenchaikul | 4 | 2 | | | | | | | | J Cui | 2 | 6 | 7$^7$ | | | | |
| | J Cui | 6 | 6 | | | J Cui | 6 | 6 | | | | | | | | | | |
| | Christian Langmo | 6 | 1 | 3 | 2 | F Maestrelli | 4 | 2 | | | | | | | | | | |
| 2 | F Maestrelli | 4 | 6 | 6 | | | | | | | | | | | | | | |