# 2001 AIG Japan Open Tennis Championships – Men's singles

Sjeng Schalken was the defending champion but lost in the quarterfinals to Michel Kratochvil.
Lleyton Hewitt won in the final 6–4, 6–2 against Kratochvil. With the victory, Hewitt became the last male player to win his debut event as a Grand Slam champion (having recently won the US Open) until Jannik Sinner in 2024.

## Seeds

The top eight seeds received a bye to the second round.
* Lleyton Hewitt (champion)
* Sjeng Schalken (quarterfinals)
* Rainer Schüttler (third round)
* Jonas Björkman (third round)
* Michel Kratochvil (final)
* Michael Chang (third round)
* Marcelo Ríos (quarterfinals)
* Francisco Clavet (quarterfinals)
* Lars Burgsmüller (third round)
* Harel Levy (second round)
* Nicolás Massú (third round)
* Andrew Ilie (first round)
* Álex Calatrava (first round)
* Wayne Arthurs (second round)
* Michael Russell (third round)
* Ramón Delgado (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

| Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| 1 | Lleyton Hewitt | 6 | 6 | | | | |
| | James Blake | 4 | 0 | | | | |
| | James Blake | 4 | 0 | 1 | Lleyton Hewitt | 6 | 6 |
| | | | | 5 | Michel Kratochvil | 4 | 2 |
| | Karol Kučera | 0 | 3 | 5 | Michel Kratochvil | 4 | 2 |
| 5 | Michel Kratochvil | 6 | 6 | | | | |

### Top half
#### Section 1

| 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 | Quarterfinals |
| | | | | 1 | L Hewitt | 6 | 6 | | | | | | | | | | |
| | J Delgado | 4 | 4 | | M-K Goellner | 2 | 2 | | | | | | | | | | |
| | M-K Goellner | 6 | 6 | | | | | | 1 | L Hewitt | 6 | 6 | | | | | |
| Q | J Thomas | 3 | 2 | | | | | | 15 | M Russell | 1 | 1 | | | | | |
| | C Mamiit | 6 | 6 | | C Mamiit | 6 | 4 | 3 | | | | | | | | | |
| | N Godwin | 4 | 6$^1$ | 15 | M Russell | 3 | 6 | 6 | | | | | | | | | |
| 15 | M Russell | 6 | 7$^7$ | | | | | | | | | | 1 | L Hewitt | 4 | 6 | 6 |
| 11 | N Massú | 6 | 6 | | | | | | | | | | 8 | F Clavet | 6 | 4 | 2 |
| | E Kempes | 4 | 4 | 11 | N Massú | 6 | 7$^7$ | | | | | | | | | | |
| | Y-I Yoon | 3 | 1 | | T Zíb | 3 | 6$^4$ | | | | | | | | | | |
| | T Zíb | 6 | 6 | | | | | | 11 | N Massú | 3 | 4 | | | | | |
| | N Thomann | 3 | 1 | | | | | | 8 | F Clavet | 6 | 6 | | | | | |
| | T Behrend | 6 | 6 | | T Behrend | 6$^7$ | 2 | | | | | | | | | | |
| | | | | 8 | F Clavet | 7$^9$ | 6 | | | | | | | | | | |

#### Section 2

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 4 | J Björkman | 6 | 6 | | | | | | | | | |
| Q | M Onoda | 4 | 4 | | WC | H Kondo | 1 | 3 | | | | | | | | | |
| WC | H Kondo | 6 | 6 | | | | | | 4 | J Björkman | 1 | 5 | | | | | |
| | J Blake | 6 | 6 | | | | | | | J Blake | 6 | 7 | | | | | |
| WC | Y Ishii | 3 | 4 | | | J Blake | 7$^7$ | 7 | | | | | | | | | |
| Q | R Žitko | 2 | 7$^7$ | 1 | 14 | W Arthurs | 6$^4$ | 5 | | | | | | | | | |
| 14 | W Arthurs | 6 | 6$^3$ | 6 | | | | | | | | | | J Blake | 4 | 6 | 6 |
| 10 | H Levy | 6 | 6 | | | | | | | | | | 7 | M Ríos | 6 | 4 | 1 |
| Q | S Iwabuchi | 3 | 3 | | 10 | H Levy | 5 | 0 | | | | | | | | | |
| Q | D Udomchoke | 6 | 4 | 6 | Q | D Udomchoke | 7 | 6 | | | | | | | | | |
| | B Cowan | 2 | 6 | 3 | | | | | Q | D Udomchoke | 3 | 2 | | | | | |
| | B Black | 6 | 6 | | | | | | 7 | M Ríos | 6 | 6 | | | | | |
| | E Taino | 4 | 1 | | | B Black | 2 | 5 | | | | | | | | | |
| | | | | | 7 | M Ríos | 6 | 7 | | | | | | | | | |

### 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 | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 6 | M Chang | 6 | 6 | | | | | | | | | |
| | A Pretzsch | 6$^3$ | 7$^7$ | 6 | | A Pretzsch | 3 | 4 | | | | | | | | | |
| | P Srichaphan | 7$^7$ | 6$^5$ | 1 | | | | | | 6 | M Chang | 6$^3$ | 2 | | | | |
| | S Sargsian | 6 | 6 | | | | | | | WC | T Suzuki | 7$^7$ | 6 | | | | |
| | A Sá | 2 | 3 | | | S Sargsian | 5 | 6 | 4 | | | | | | | | |
| WC | T Suzuki | 5 | 6 | 6 | WC | T Suzuki | 7 | 4 | 6 | | | | | | | | |
| 12 | A Ilie | 7 | 2 | 4 | | | | | | | | | | WC | T Suzuki | 3 | 3 |
| 16 | R Delgado | 6 | 6 | | | | | | | | | | | | K Kučera | 6 | 6 |
| WC | G Motomura | 4 | 4 | | 16 | R Delgado | 4 | 4 | | | | | | | | | |
| | K Kučera | 6 | 4 | 6 | | K Kučera | 6 | 6 | | | | | | | | | |
| | A Simoni | 3 | 6 | 1 | | | | | | | K Kučera | 6 | 6 | | | | |
| | M Lee | 4 | 2 | | | | | | | 3 | R Schüttler | 2 | 2 | | | | |
| | M Larsson | 6 | 6 | | | M Larsson | 3 | 5 | | | | | | | | | |
| | | | | | 3 | R Schüttler | 6 | 7 | | | | | | | | | |

#### 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 | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 5 | M Kratochvil | 7$^7$ | 1 | 6 | | | | | | | | |
| | O Fukárek | 6 | 7$^7$ | | | O Fukárek | 6$^3$ | 6 | 4 | | | | | | | | |
| Q | D Vacek | 2 | 6$^3$ | | | | | | | 5 | M Kratochvil | 6 | 6 | | | | |
| | H-T Lee | 7$^{13}$ | 6 | | | | | | | 9 | L Burgsmüller | 3 | 2 | | | | |
| | M Hantschk | 6$^{11}$ | 4 | | | H-T Lee | 6 | 3 | 5 | | | | | | | | |
| | M Llodra | 6$^3$ | 6 | 2 | 9 | L Burgsmüller | 3 | 6 | 7 | | | | | | | | |
| 9 | L Burgsmüller | 7$^7$ | 2 | 6 | | | | | | | | | | 5 | M Kratochvil | 6 | 6 |
| 13 | Á Calatrava | 3 | 1 | | | | | | | | | | | 2 | S Schalken | 3 | 4 |
| | I Heuberger | 6 | 6 | | | I Heuberger | 3 | 6 | 6 | | | | | | | | |
| Q | N Behr | 6 | 6 | | Q | N Behr | 6 | 4 | 4 | | | | | | | | |
| WC | T Terachi | 2 | 1 | | | | | | | | I Heuberger | 2 | 2 | | | | |
| | I Labadze | 7$^7$ | 3 | 5 | | | | | | 2 | S Schalken | 6 | 6 | | | | |
| | C Vinck | 6$^3$ | 6 | 7 | | C Vinck | 3 | 4 | | | | | | | | | |
| | | | | | 2 | S Schalken | 6 | 6 | | | | | | | | | |