# 2005 AIG Japan Open Tennis Championships – Men's singles

Jiří Novák was the defending champion, but did not participate.
Wesley Moodie won the title, defeating Mario Ančić in the final 1–6, 7–6$^{(9–7)}$, 6–4.

## Seeds

All seeds receive a bye into the second round.
* Mariano Puerta (third round)
* Radek Štěpánek (quarterfinals)
* Robby Ginepri (quarterfinals)
* Taylor Dent (quarterfinals)
* Mario Ančić (final)
* Mikhail Youzhny (second round)
* Jarkko Nieminen (semifinals)
* Vince Spadea (second round)
* Paradorn Srichaphan (third round)
* Kenneth Carlsen (third round)
* Luis Horna (third round)
* Cyril Saulnier (third round)
* Gilles Müller (third round)
* Ivo Minář (second round)
* Robin Vik (second round)
* Juan Mónaco (second 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 |
| | Marcos Baghdatis | 1 | 6$^4$ | | | | | | | | | | | |
| 5 | Mario Ančić | 6 | 7$^7$ | | | | | | | | | | | |
| 5 | Mario Ančić | 6 | 7$^7$ | | 5 | Mario Ančić | 6 | 6 | | | | | | |
| | | | | | | Björn Phau | 2 | 1 | | | | | | |
| 3 | Robby Ginepri | 4 | 3 | | | Björn Phau | 2 | 1 | | | | | | |
| | Björn Phau | 6 | 6 | | | | | | | | | | | |
| | Björn Phau | 6 | 6 | | | | | | | 5 | Mario Ančić | 6 | 6$^7$ | 4 |
| | | | | | | | | | | | Wesley Moodie | 1 | 7$^9$ | 6 |
| 7 | Jarkko Nieminen | 6 | 5 | 7$^7$ | | | | | | | | | | | Wesley Moodie | 1 | 7$^9$ | 6 |
| 4 | Taylor Dent | 4 | 7 | 6$^3$ | | | | | | | | | | |
| 4 | Taylor Dent | 4 | 7 | 6$^3$ | 7 | Jarkko Nieminen | 6 | 1 | 6$^4$ | | | | | |
| | | | | | | Wesley Moodie | 4 | 6 | 7$^7$ | | | | | |
| | Wesley Moodie | 7$^7$ | 7$^8$ | | | Wesley Moodie | 4 | 6 | 7$^7$ | | | | | |
| 2 | Radek Štěpánek | 6$^2$ | 6$^6$ | | | | | | | | | | | |

### 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 | M Puerta | 6 | 6 | | | | | | | | | | |
| Q | T Iwami | 6$^9$ | 4 | | Q | E Taino | 3 | 4 | | | | | | | | | | |
| Q | E Taino | 7$^{11}$ | 6 | | | | | | | 1 | M Puerta | 2 | 7$^{13}$ | 5 | | | | |
| | M Baghdatis | 6 | 6 | | | | | | | | M Baghdatis | 6 | 6$^{11}$ | 7 | | | | |
| | J Tipsarević | 4 | 4 | | | M Baghdatis | 6 | 6 | | | | | | | | | | |
| | | | | | 14 | I Minář | 4 | 2 | | | | | | | | | | |
| | | | | | | | | | | | | | | | | M Baghdatis | 1 | 6$^4$ |
| | | | | | | | | | | | | | | | 5 | M Ančić | 6 | 7$^7$ |
| | | | | | 12 | C Saulnier | 6 | 6$^5$ | 7 | | | | | | | | | |
| Q | R Sluiter | 6 | 6 | | Q | R Sluiter | 3 | 7$^7$ | 5 | | | | | | | | | |
| | L Burgsmüller | 3 | 1 | | | | | | | 12 | C Saulnier | 2 | 1 | | | | | |
| Q | J-M Gambill | 6 | 5 | 6 | | | | | | 5 | M Ančić | 6 | 6 | | | | | |
| | P Wessels | 2 | 7 | 3 | Q | J-M Gambill | 6 | 3 | 4 | | | | | | | | | |
| | | | | | 5 | M Ančić | 3 | 6 | 6 | | | | | | | | | |

#### Section 2

| 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 | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 3 | R Ginepri | 6 | 6 | | | | | | | | | |
| WC | G Motomura | 2 | 4 | | PR | A Popp | 4 | 0 | | | | | | | | | |
| PR | A Popp | 6 | 6 | | | | | | | 3 | R Ginepri | 6 | 6 | | | | |
| | A Waske | 3 | 7$^7$ | 7$^7$ | | | | | | 13 | G Müller | 4 | 4 | | | | |
| | J Gimelstob | 6 | 6$^5$ | 6$^3$ | | A Waske | 5 | 6 | 1 | | | | | | | | |
| | | | | | 13 | G Müller | 7 | 4 | 6 | | | | | | | | |
| | | | | | | | | | | | | | | 3 | R Ginepri | 4 | 3 |
| | | | | | | | | | | | | | | | B Phau | 6 | 6 |
| | | | | | 10 | K Carlsen | 7$^7$ | 7$^{11}$ | | | | | | | | | |
| WC | T Ittogi | 0 | 1 | | | N Lapentti | 6$^1$ | 6$^9$ | | | | | | | | | |
| | N Lapentti | 6 | 6 | | | | | | | 10 | K Carlsen | 1 | 2 | | | | |
| | S Koubek | 7$^9$ | 4 | 6$^5$ | | | | | | | B Phau | 6 | 6 | | | | |
| | B Phau | 6$^7$ | 6 | 7$^7$ | | B Phau | 6 | 7 | | | | | | | | | |
| | | | | | 8 | V Spadea | 4 | 5 | | | | | | | | | |

### Bottom half
#### Section 3

| 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 | Quarterfinals |
| | | | | | 7 | J Nieminen | 6 | 6 | | | | | | | | | | | |
| Q | G Soeda | 4 | 6 | 2 | | R Schüttler | 1 | 1 | | | | | | | | | | | |
| | R Schüttler | 6 | 4 | 6 | | | | | | 7 | J Nieminen | 2 | 7$^8$ | 7 | | | | | |
| | P Kohlschreiber | 3 | 6$^1$ | | | | | | | 9 | P Srichaphan | 6 | 6$^6$ | 5 | | | | | |
| WC | T Terachi | 6 | 7$^7$ | | WC | T Terachi | 1 | 4 | | | | | | | | | | | |
| | | | | | 9 | P Srichaphan | 6 | 6 | | | | | | | | | | | |
| | | | | | | | | | | | | | | | 7 | J Nieminen | 6 | 5 | 7$^7$ |
| | | | | | | | | | | | | | | | 4 | T Dent | 4 | 7 | 6$^3$ |
| | | | | | 16 | J Mónaco | 6 | 1 | 4 | | | | | | | | | | |
| | W Arthurs | 6 | 1 | 7$^7$ | | W Arthurs | 4 | 6 | 6 | | | | | | | | | | |
| WC | T Suzuki | 3 | 6 | 6$^2$ | | | | | | | W Arthurs | 4 | 7$^7$ | 3 | | | | | |
| PR | D Tursunov | 3 | 6 | 6 | | | | | | 4 | T Dent | 6 | 6$^5$ | 6 | | | | | |
| | G García López | 6 | 4 | 1 | PR | D Tursunov | 3 | 6$^3$ | | | | | | | | | | | |
| | | | | | 4 | T Dent | 6 | 7$^7$ | | | | | | | | | | | |

#### Section 4

| 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 |
| | | | | 6 | M Youzhny | 1 | 6 | 3 | | | | | | | | | |
| | W Moodie | 6 | 6 | | W Moodie | 6 | 3 | 6 | | | | | | | | | |
| | J Wang | 1 | 4 | | | | | | | W Moodie | 7$^7$ | 6$^2$ | 6 | | | | |
| | D Udomchoke | 6$^5$ | 4 | | | | | | 11 | L Horna | 6$^4$ | 7$^7$ | 4 | | | | |
| | R Karanušić | 7$^7$ | 6 | | R Karanušić | 2 | 5 | | | | | | | | | | |
| | | | | 11 | L Horna | 6 | 7 | | | | | | | | | | |
| | | | | | | | | | | | | | | | W Moodie | 7$^7$ | 7$^8$ |
| | | | | | | | | | | | | | | 2 | R Štěpánek | 6$^2$ | 6$^6$ |
| | | | | 15 | R Vik | 2 | 4 | | | | | | | | | | |
| Q | D Gremelmayr | 2 | 6$^3$ | | K Kim | 6 | 6 | | | | | | | | | | |
| | K Kim | 6 | 7$^7$ | | | | | | | K Kim | 1 | 3 | | | | | |
| | J Vaněk | 7$^7$ | 7$^7$ | | | | | | 2 | R Štěpánek | 6 | 6 | | | | | |
| | L Dlouhý | 6$^4$ | 6$^5$ | | J Vaněk | 5 | 4 | | | | | | | | | | |
| | | | | 2 | R Štěpánek | 7 | 6 | | | | | | | | | | |