# 2013 U.S. National Indoor Tennis Championships – Men's singles

Jürgen Melzer was the defending champion, but lost in the first round to Igor Sijsling. Kei Nishikori won the title, defeating Feliciano López in the final, 6–2, 6–3.

## Seeds

* Marin Čilić (quarterfinals)
* Milos Raonic (first round)
* John Isner (first round)
* Sam Querrey (second round)
* Kei Nishikori (champion)
* Tommy Haas (second round, withdrew because of a viral illness)
* Alexandr Dolgopolov (quarterfinals)
* Fernando Verdasco (withdrew because of a neck injury)

## 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 |
| 5 | Kei Nishikori | 6 | 0 | | | | | |
| | Marinko Matosevic | 4 | 0$^r$ | | | | | |
| | Marinko Matosevic | 4 | 0$^r$ | | 5 | Kei Nishikori | 6 | 6 |
| | | | | | | Feliciano López | 2 | 3 |
| | Denis Istomin | 2 | 6 | 3 | | Feliciano López | 2 | 3 |
| | Feliciano López | 6 | 3 | 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 | M Čilić | 4 | 6 | 6 | | | | | | | | | | | | | | |
| | I Dodig | 6 | 2 | 3 | 1 | M Čilić | 7$^7$ | 3 | 7$^9$ | | | | | | | | | |
| | J Melzer | 4 | 6$^3$ | | | I Sijsling | 6$^2$ | 6 | 6$^7$ | | | | | | | | | |
| | I Sijsling | 6 | 7$^7$ | | | | | | | 1 | M Čilić | 4 | 2 | | | | | |
| Q | D Young | 5 | | | | | | | | 5 | K Nishikori | 6 | 6 | | | | | |
| | X Malisse | 1$^r$ | | | Q | D Young | 3 | 3 | | | | | | | | | | |
| Q | I Marchenko | 4 | 5 | | 5 | K Nishikori | 6 | 6 | | | | | | | | | | |
| 5 | K Nishikori | 6 | 7 | | | | | | | | | | | | 5 | K Nishikori | 6 | 0 |
| 4 | S Querrey | 6 | 6 | | | | | | | | | | | | | M Matosevic | 4 | 0$^r$ |
| | A Falla | 3 | 3 | | 4 | S Querrey | 6 | 4 | 5 | | | | | | | | | |
| | G Soeda | 6$^6$ | 4 | | | M Matosevic | 3 | 6 | 7 | | | | | | | | | |
| | M Matosevic | 7$^8$ | 6 | | | | | | | | M Matosevic | 6$^6$ | 6 | 6 | | | | |
| WC | S Johnson | 6$^4$ | 4 | | | | | | | 7 | A Dolgopolov | 7$^8$ | 2 | 4 | | | | |
| Q | R Williams | 7$^7$ | 6 | | Q | R Williams | 4 | 6 | 4 | | | | | | | | | |
| | B Phau | 3 | 4 | | 7 | A Dolgopolov | 6 | 4 | 6 | | | | | | | | | |
| 7 | A Dolgopolov | 6 | 6 | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| Q | A Bogomolov Jr. | 2 | 4 | | | | | | | | | | | | | |
| LL | M Russell | 6 | 6 | | LL | M Russell | 6 | 6 | | | | | | | | |
| | R Harrison | 4 | 7$^7$ | 6$^2$ | | Ł Kubot | 2 | 4 | | | | | | | | |
| | Ł Kubot | 6 | 6$^4$ | 7$^7$ | | | | | LL | M Russell | 4 | 6$^5$ | | | | |
| | Y-h Lu | 6 | 6$^3$ | 4 | | | | | | D Istomin | 6 | 7$^7$ | | | | |
| | L Hewitt | 2 | 7$^7$ | 6 | | L Hewitt | 1 | 2 | | | | | | | | |
| | D Istomin | 6 | 6 | | | D Istomin | 6 | 6 | | | | | | | | |
| 3 | J Isner | 4 | 3 | | | | | | | | | | D Istomin | 2 | 6 | 3 |
| 6 | T Haas | 7$^8$ | 6 | | | | | | | | | | F López | 6 | 3 | 6 |
| | E Donskoy | 6$^6$ | 4 | | 6 | T Haas | | | | | | | | | | |
| | B Becker | 6 | 3 | 4 | | F López | w/o | | | | | | | | | |
| | F López | 4 | 6 | 6 | | | | | | F López | 6 | 6 | | | | |
| | F Mayer | 6 | 3 | 2 | | | | | WC | J Sock | 4 | 3 | | | | |
| WC | J Blake | 4 | 6 | 6 | WC | J Blake | 5 | 4 | | | | | | | | |
| WC | J Sock | 6 | 5 | 7 | WC | J Sock | 7 | 6 | | | | | | | | |
| 2 | M Raonic | 3 | 7 | 5 | | | | | | | | | | | | |

## Qualifying
### Seeds

* Michael Russell (qualifying competition, lucky loser)
* Tim Smyczek (first round)
* Philipp Petzschner (first round)
* Matthew Ebden (qualifying competition)
* Alex Bogomolov Jr. (qualified)
* Vasek Pospisil (first round)
* Illya Marchenko (qualified)
* Denis Kudla (first round)

### Qualifiers

* Donald Young
* Rhyne Williams
* Alex Bogomolov Jr.
* Illya Marchenko

### Lucky losers

* Michael Russell

### Draw
#### First qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Michael Russell | 7 | 6 | | | | | |
| WC | Christian Harrison | 5 | 4 | | | | | |
| WC | Christian Harrison | 5 | 4 | 1 | Michael Russell | 6 | 3 | 6$^7$ |
| | | | | | Donald Young | 4 | 6 | 7$^9$ |
| | Donald Young | 6 | 6 | | Donald Young | 4 | 6 | 7$^9$ |
| 8 | Denis Kudla | 2 | 1 | | | | | |

#### Second qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition |
| 2 | Tim Smyczek | 6 | 1 | 2 | | | |
| | Rhyne Williams | 2 | 6 | 6 | | | |
| | Rhyne Williams | 2 | 6 | 6 | Rhyne Williams | 7$^7$ | 6 |
| | | | | | Daniel Muñoz de la Nava | 6$^4$ | 4 |
| | Daniel Muñoz de la Nava | 6 | 7$^7$ | | Daniel Muñoz de la Nava | 6$^4$ | 4 |
| 6 | Vasek Pospisil | 4 | 6$^3$ | | | | |

#### Third qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 3 | Philipp Petzschner | 1 | 6$^6$ | | | | | |
| | Ivo Karlović | 6 | 7$^8$ | | | | | |
| | Ivo Karlović | 6 | 7$^8$ | | Ivo Karlović | 3 | 6 | 4 |
| | | | | 5 | Alex Bogomolov Jr. | 6 | 3 | 6 |
| | Sekou Bangoura | 5 | 1 | 5 | Alex Bogomolov Jr. | 6 | 3 | 6 |
| 5 | Alex Bogomolov Jr. | 7 | 6 | | | | | |

#### Fourth qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Matthew Ebden | 6 | 6 | | | | | | |
| WC | Connor Glennon | 3 | 4 | | | | | | |
| WC | Connor Glennon | 3 | 4 | | 4 | Matthew Ebden | 6 | 3 | 1 |
| | | | | | 7 | Illya Marchenko | 4 | 6 | 6 |
| | Andrey Golubev | 6$^4$ | 6 | 6$^4$ | 7 | Illya Marchenko | 4 | 6 | 6 |
| 7 | Illya Marchenko | 7$^7$ | 2 | 7$^7$ | | | | | |