Swimming at the 2009 World Aquatics Championships – Women's 50 metre butterfly explained

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The heats for the women's 50 m butterfly race at the 2009 World Championships took place in the morning and evening of 31 July, with the final in the evening session of 1 August at the Foro Italico in Rome, Italy.

Records

Prior to this competition, the existing world and competition records were as follows:

World record		25.33		align=right	19 April 2009
Championship record		25.82		align=right	30 March 2007

The following records were established during the competition:

Date	Round	Time	Record
31 July	Heat 10	25.74	CR
31 July	Heat 13	25.44	CR
31 July	Semifinal 1	25.28	WR
31 July	Semifinal 2	25.07	WR

Results

Heats

Rank	Time	Heat	Lane	Notes
1	25.44	13	4	CR, NR
2	25.58	14	4
3	25.62	13	7	NR
4	25.74	10	3
5	25.83	14	5
6	25.84	13	6	NR
7	25.86	14	3	NR
8	26.00	14	2	AS
9	26.06	13	5
10	26.07	13	2	SA
11	26.11	13	8
12	26.21	12	5
12	26.21	14	8
14	26.27	14	9
15	26.35	14	6
16	26.36	12	8
17	26.41	12	4
17	26.41	13	3
19	26.46	12	1
20	26.49	12	2	NR
21	26.53	12	3
22	26.55	14	7
23	26.59	12	7
23	26.59	13	9
25	26.68	11	4	NR
26	26.71	11	8
26	26.71	12	6
28	26.76	10	5
29	26.77	12	0
30	26.79	11	3
31	26.80	12	9
32	26.82	14	1
33	26.85	14	0
34	27.07	13	9	NR
35	27.13	13	1
36	27.16	11	6
37	27.23	11	5
38	27.28	11	2
39	27.31	13	0
40	27.37	10	4
41	27.39	10	9
42	27.43	11	0
43	27.44	10	8
44	27.50	10	6	NR
45	27.52	9	5
45	27.52	9	0
47	27.53	9	7
48	27.56	11	7
49	27.61	11	1
50	27.78	9	3
51	27.82	9	2
52	27.88	9	6
53	27.96	9	9
54	27.97	8	5	NR
55	27.98	9	8
56	28.12	9	1
57	28.18	9	4
58	28.20	10	1
59	28.23	7	5
60	28.25	8	3
61	28.36	8	6
62	28.38	10	0
63	28.48	8	4
64	28.58	7	4	NR
65	28.62	8	2
65	28.62	10	2	NR
67	28.88	7	3
68	29.01	7	1	NR
69	29.16	8	7
70	29.21	8	8
71	29.32	7	2	NR
72	29.34	6	3
73	29.35	7	7
74	29.48	7	8
75	29.50	7	6
76	29.53	6	6
77	29.56	6	2	NR
78	29.60	7	1
79	29.63	6	4
80	29.66	8	9
81	29.69	5	1
82	29.72	5	8
83	29.85	5	6
84	29.86	6	7	NR
85	30.05	8	1
86	30.12	5	0
87	30.13	4	5
88	30.18	6	5
89	30.24	6	9
90	30.29	3	2
91	30.33	5	2
92	30.47	7	0
93	30.50	4	5
94	30.53	5	7
95	30.63	3	7
96	30.65	3	6
96	30.65	6	1
98	30.74	8	0
99	30.79	5	5
100	30.97	4	4
101	31.05	2	2
102	31.06	6	0
103	31.30	3	4
104	31.33	3	8
105	31.35	4	6
105	31.35	4	0
107	31.41	4	9
108	31.45	4	2
109	31.69	3	0
110	31.79	4	1
111	31.80	4	3
112	31.92	2	2
113	32.14	3	1
114	32.17	3	3
115	32.20	2	5
115	32.20	2	7
117	32.34	2	8
118	32.39	2	4
119	32.59	4	8
120	32.65	2	1
121	32.82	3	9
122	32.83	2	6
123	32.92	3	5
124	33.13	5	3
125	33.64	6	8
126	33.76	1	5
127	34.67	1	3
128	34.96	1	2
129	36.63	5	4
130	37.54	2	9
131	43.87	2	0
132	44.33	1	6
–	DNS	5	9
–	DSQ	1	4
–	DSQ	11	9

Semifinals

Rank	Time	Heat	Lane	Notes
1	25.07	2	4	WR
2	25.28	1	4	NR
3	25.53	2	5	NR
4	25.58	2	3	OC
5	25.59	1	6	AS
6	25.76	1	5
7	25.85	2	7	SA
8	25.87	2	8	NR
9	25.90	2	6
10	25.94	1	7
11	26.00	1	3
12	26.00	2	1
13	26.02	1	2
14	26.16	1	1
15	26.21	2	2
16	26.33	1	8	NR

Final

Rank	Time	Lane	Notes
	25.48	6	OC
	25.57	2	AS
	25.58	3
4	25.59	4
5	25.63	5
6	25.66	7
7	25.92	8
8	26.12	1