Men's singles
2003 AIG Japan Open Tennis Championships
Champion	Rainer Schüttler
Runner-up	Sébastien Grosjean
Score	7–6(7–5), 6–2
Draw	48 (6 Q / 4 WC )
Seeds	16

Kenneth Carlsen was the defending champion but lost in the third round to Hyung-Taik Lee.

Rainer Schüttler won in the final 7–6^(7–5), 6–2 against Sébastien Grosjean.

Seeds

All sixteen seeds received a bye to the second round.

Draw

Finals

	Semifinals							Final
	1	Rainer Schüttler	6	6
		Cyril Saulnier	3	2
								1	Rainer Schüttler	77	6
								2	Sébastien Grosjean	65	2
	3	Paradorn Srichaphan	6	3	4
	2	Sébastien Grosjean	4	6	6

Top half

Section 1

	First round							Second round							Third round							Quarterfinals
								1	R Schüttler	6	6
	WC	S Iwabuchi	77	6				WC	S Iwabuchi	0	4
		C Mamiit	64	2											1	R Schüttler	6	6
		R Kendrick	77	6												R Kendrick	3	2
		W Arthurs	63	4					R Kendrick	6	3	6
								13	B Vahaly	2	6	4
																						1	R Schüttler	6	6
																							S Draper	3	3
								LL	E Taino	2	65
	Q	J Vacek	3	64					S Draper	6	77
		S Draper	6	77												S Draper	7	6
		I Heuberger	2	61											6	N Kiefer	5	2
		A Bogomolov Jr.	6	77					A Bogomolov Jr.	5	67
								6	N Kiefer	7	79

Section 2

	First round							Second round							Third round							Quarterfinals
								4	J Novák	77	6
	Q	B Phau	61	77	77			Q	B Phau	62	2
		J Salzenstein	77	64	63										4	J Novák	6	5	4
		J Gimelstob	65	6	1											C Saulnier	4	7	6
		C Saulnier	77	3	6				C Saulnier	78	77
								15	L Burgsmüller	66	64
																							C Saulnier	5
																						5	M Philippoussis	2r
								10	M Ančić	6	7
		W Eschauer	0	4				Q	T Iwami	2	5
	Q	T Iwami	6	6											10	M Ančić	4	5
		F Browne	6	6											5	M Philippoussis	6	7
	WC	T Terachi	3	4					F Browne	4	3
								5	M Philippoussis	6	6

Bottom half

Section 3

	First round							Second round							Third round							Quarterfinals
								7	H-T Lee	6	63	6
	Q	G Weiner	4	2					F Verdasco	3	77	3
		F Verdasco	6	6											7	H-T Lee	6	6
		M Vassallo Argüello	0	3											9	K Carlsen	3	4
	WC	G Motomura	6	6				WC	G Motomura	2	64
								9	K Carlsen	6	77
																						7	H-T Lee	6	65	3
																						3	P Srichaphan	4	77	6
								14	W Moodie	1	63
		A Waske	65	3				WC	T Suzuki	6	77
	WC	T Suzuki	77	6											WC	T Suzuki	2	63
		D Norman	7	6											3	P Srichaphan	6	77
	Q	G Bastl	5	4					D Norman	6	63	62
								3	P Srichaphan	4	77	77

Section 4

	First round							Second round							Third round							Quarterfinals
								8	J-M Gambill	6	6
		I Miranda	6	4	4				B Ulihrach	3	4
		B Ulihrach	2	6	6										8	J-M Gambill	6	7
		T Berdych	62	6	3										Q	M Kratochvil	3	5
	Q	M Kratochvil	77	4	6			Q	M Kratochvil	6	6
								12	J van Lottum	2	3
																						8	J-M Gambill	3	64
																						2	S Grosjean	6	77
								16	G Carraz	5	6	5
		A Vinciguerra	6	4	1				D van Scheppingen	7	1	7
		D van Scheppingen	4	6	6											D van Scheppingen	3	63
		R Söderling	4	4											2	S Grosjean	6	77
		I Karlović	6	6					I Karlović	3	68
								2	S Grosjean	6	710

References

• 2003 AIG Japan Open Tennis Championships Draw