# 2019 Oracle Challenger Series – Houston – Men's singles

Bradley Klahn was the defending champion but lost in the third round to Michael Mmoh.
Marcos Giron won the title after defeating Ivo Karlović 7–5, 6–7$^{(5–7)}$, 7–6$^{(11–9)}$ in the final.

## Seeds

All seeds receive a bye into the second round.
* Tennys Sandgren (third round)
* Bradley Klahn (third round)
* Ivo Karlović (final)
* Marcos Giron (champion)
* Jason Jung (quarterfinals)
* Christopher O'Connell (semifinals)
* Darian King (second round)
* Mitchell Krueger (semifinals)
* Alexey Vatutin (third round)
* Donald Young (second round)
* Adrián Menéndez Maceiras (third round)
* Peđa Krstin (third round)
* Jenson Brooksby (third round)
* Michael Mmoh (quarterfinals, retired)
* Michael Redlicki (quarterfinals)
* Sekou Bangoura (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

| Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final | Final |
| 15 | Michael Redlicki | 4 | 4 | | | | | | | | | | | |
| 8 | Mitchell Krueger | 6 | 6 | | | | | | | | | | | |
| 8 | Mitchell Krueger | 6 | 6 | | 8 | Mitchell Krueger | 6$^4$ | 2 | | | | | | |
| | | | | | 4 | Marcos Giron | 7$^7$ | 6 | | | | | | |
| 4 | Marcos Giron | 6 | 2 | 6 | 4 | Marcos Giron | 7$^7$ | 6 | | | | | | |
| 5 | Jason Jung | 1 | 6 | 2 | | | | | | | | | | |
| 5 | Jason Jung | 1 | 6 | 2 | | | | | | 4 | Marcos Giron | 7 | 6$^5$ | 7$^{11}$ |
| | | | | | | | | | | 3 | Ivo Karlović | 5 | 7$^7$ | 6$^9$ |
| Q | Alexis Galarneau | 6$^3$ | 6$^7$ | | | | | | | | | | | | 3 | Ivo Karlović | 5 | 7$^7$ | 6$^9$ |
| 3 | Ivo Karlović | 7$^7$ | 7$^9$ | | | | | | | | | | | |
| 3 | Ivo Karlović | 7$^7$ | 7$^9$ | | 3 | Ivo Karlović | 6$^5$ | 6 | 6 | | | | | |
| | | | | | 6 | Christopher O'Connell | 7$^7$ | 3 | 4 | | | | | |
| 6 | Christopher O'Connell | 5 | | | 6 | Christopher O'Connell | 7$^7$ | 3 | 4 | | | | | |
| 14 | Michael Mmoh | 0$^r$ | | | | | | | | | | | | |

### 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 | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 1 | T Sandgren | 6 | 7 | | | | | | | | | | |
| | E Leshem | 6 | 6 | | | E Leshem | 3 | 5 | | | | | | | | | | |
| | Christopher Heyman | 4 | 4 | | | | | | | 1 | T Sandgren | 7$^7$ | 4 | 4 | | | | |
| | G Nanda | 6 | 6 | | | | | | | 15 | Mi Redlicki | 6$^5$ | 6 | 6 | | | | |
| WC | O Crawford | 4 | 3 | | | G Nanda | 3 | 3 | | | | | | | | | | |
| | | | | | 15 | Mi Redlicki | 6 | 6 | | | | | | | | | | |
| | | | | | | | | | | | | | | | 15 | Mi Redlicki | 4 | 4 |
| | | | | | | | | | | | | | | | 8 | M Krueger | 6 | 6 |
| | | | | | 12 | P Krstin | 6 | 1 | 6 | | | | | | | | | |
| | N Chappell | 6 | 3 | 7$^7$ | | N Chappell | 1 | 6 | 1 | | | | | | | | | |
| | S Fanselow | 1 | 6 | 6$^5$ | | | | | | 12 | P Krstin | 6$^4$ | 4 | | | | | |
| WC | Z Khan | 4 | 3 | | | | | | | 8 | M Krueger | 7$^7$ | 6 | | | | | |
| | F Meligeni Alves | 6 | 6 | | | F Meligeni Alves | 2 | 2 | | | | | | | | | | |
| | | | | | 8 | M Krueger | 6 | 6 | | | | | | | | | | |

#### Section 2

| 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 | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | 4 | M Giron | 7$^7$ | 6$^7$ | 6 | | | | | | | | | | |
| WC | B Holt | 6 | 7 | WC | B Holt | 6$^4$ | 7$^9$ | 2 | | | | | | | | | | |
| | C Sinclair | 1 | 5 | | | | | | 4 | M Giron | 6 | 4 | 6 | | | | | |
| | R Matos | 6$^3$ | 4 | | | | | | 13 | J Brooksby | 2 | 6 | 3 | | | | | |
| | G Villanueva | 7$^7$ | 6 | | G Villanueva | 2 | 2 | | | | | | | | | | | |
| | | | | 13 | J Brooksby | 6 | 6 | | | | | | | | | | | |
| | | | | | | | | | | | | | | 4 | M Giron | 6 | 2 | 6 |
| | | | | | | | | | | | | | | 5 | J Jung | 1 | 6 | 2 |
| | | | | 9 | A Vatutin | 1 | 7 | 6 | | | | | | | | | | |
| | A Sarkissian | 1 | 1 | | D Hidalgo | 6 | 5 | 3 | | | | | | | | | | |
| | D Hidalgo | 6 | 6 | | | | | | 9 | A Vatutin | 5 | 2 | | | | | | |
| WC | Sumit Sarkar | 1 | 0 | | | | | | 5 | J Jung | 7 | 6 | | | | | | |
| | D Nguyen | 6 | 6 | | D Nguyen | 3 | 2 | | | | | | | | | | | |
| | | | | 5 | J Jung | 6 | 6 | | | | | | | | | | | |

### Bottom half
#### Section 3

| 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 | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | 7 | D King | 6$^3$ | 5 | | | | | | | | | | |
| | G Escobar | 6 | 7$^7$ | | G Escobar | 7$^7$ | 7 | | | | | | | | | | |
| | E Zhu | 2 | 6$^4$ | | | | | | | G Escobar | 3 | 3 | | | | | |
| Q | A Galarneau | 6 | 6 | | | | | | Q | A Galarneau | 6 | 6 | | | | | |
| | G López Villaseñor | 3 | 3 | Q | A Galarneau | 3 | 6 | 6 | | | | | | | | | |
| | | | | 10 | D Young | 6 | 3 | 0 | | | | | | | | | |
| | | | | | | | | | | | | | | Q | A Galarneau | 6$^3$ | 6$^7$ |
| | | | | | | | | | | | | | | 3 | I Karlović | 7$^7$ | 7$^9$ |
| | | | | 16 | S Bangoura | 0 | 6 | 6 | | | | | | | | | |
| | A Ritschard | 3 | 5 | | P Heller | 6 | 4 | 2 | | | | | | | | | |
| | Peter Heller | 6 | 7 | | | | | | 16 | S Bangoura | 6$^5$ | 6 | 4 | | | | |
| | L Caruana | 6 | 6 | | | | | | 3 | I Karlović | 7$^7$ | 2 | 6 | | | | |
| WC | Mohamed Abdel-Aziz | 2 | 4 | | L Caruana | 5 | 4 | | | | | | | | | | |
| | | | | 3 | I Karlović | 7 | 6 | | | | | | | | | | |

#### 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 | Third round | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 6 | C O'Connell | 6 | 5 | 6 | | | | | | | | |
| | MF Descotte | 4 | 3 | | | A Vavassori | 3 | 7 | 4 | | | | | | | | |
| | A Vavassori | 6 | 6 | | | | | | | 6 | C O'Connell | 7$^7$ | 6 | | | | |
| | Gage Brymer | 2 | 6$^5$ | | | | | | | 11 | A Menéndez Maceiras | 6$^3$ | 4 | | | | |
| | C Altamirano | 6 | 7$^7$ | | | C Altamirano | 4 | 0 | | | | | | | | | |
| | | | | | 11 | A Menéndez Maceiras | 6 | 6 | | | | | | | | | |
| | | | | | | | | | | | | | | | 6 | C O'Connell | 5 |
| | | | | | | | | | | | | | | | 14 | M Mmoh | 0$^r$ |
| | | | | | 14 | M Mmoh | 4 | 6 | 6 | | | | | | | | |
| | E King | 6 | 4 | 5 | | R Sarmiento | 6 | 4 | 4 | | | | | | | | |
| | R Sarmiento | 4 | 6 | 7 | | | | | | 14 | M Mmoh | 5 | 7$^7$ | 7$^7$ | | | |
| | FC Jianu | 6 | 6 | | | | | | | 2 | B Klahn | 7 | 6$^5$ | 6$^5$ | | | |
| Q | Alafia Ayeni | 4 | 2 | | | FC Jianu | 5 | 3 | | | | | | | | | |
| | | | | | 2 | B Klahn | 7 | 6 | | | | | | | | | |