Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Match | Date | Opponent | Venue | Result | Attnd. | Report |
| --- | --- | --- | --- | --- | --- | --- |
| 1.0 | 7 September 2008 | Bayern Munich | H | 0:3 (0:2) | 1279.0 | Report |
| 2.0 | 14 September 2008 | SC Freiburg | A | 0:1 (0:0) | 1000.0 | Report |
| 3.0 | 21 September 2008 | HSV Borussia Friedenstal | H | 3:0 (1:0) | 808.0 | Report |
| 4.0 | 28 September 2008 | Hamburger SV | A | 1:3 (0:2) | 480.0 | Report |
| 5.0 | 5 October 2008 | FCR 2001 Duisburg | H | 2:2 (0:1) | 865.0 | Report |
| 6.0 | 12 October 2008 | TSV Crailsheim | A | 0:2 (0:1) | 389.0 | Report |
| 7.0 | 26 October 2008 | FF USV Jena | A | 0:5 (0:3) | 1650.0 | Report |
| 8.0 | 2 November 2008 | SG Essen-Schönebeck | H | 4:0 (1:0) | 837.0 | Report |
| 9.0 | 17 September 2008 | SC 07 Bad Neuenahr | A | 2:2 (1:0) | 320.0 | Report |
| 10.0 | 1 April 2009 | 1. FFC Frankfurt | H | 2:2 (1:0) | 1823.0 | Report |
| 11.0 | 22 October 2008 | VfL Wolfsburg | A | 1:5 (0:1) | 631.0 | Report |
| 12.0 | 14 December 2008 | Bayern Munich | A | 2:1 (0:1) | 463.0 | Report |
| 13.0 | 18 March 2009 | SC Freiburg | H | 7:1 (3:0) | 655.0 | Report |
| 14.0 | 1 March 2009 | HSV Borussia Friedenstal | A | 0:4 (0:1) | 683.0 | Report |
| 15.0 | 15 March 2009 | Hamburger SV | H | 3:1 (0:0) | 744.0 | Report |
| 16.0 | 22 March 2009 | FCR 2001 Duisburg | A | 0:3 (0:2) | 1490.0 | Report |
| 17.0 | 29 March 2009 | TSV Crailsheim | H | 4:0 (1:0) | 776.0 | Report |
| 18.0 | 18 April 2009 | FF USV Jena | H | 3:2 (1:0) | 804.0 | Report |
| 19.0 | 3 May 2009 | SG Essen-Schönebeck | A | 1:5 (1:3) | 1342.0 | Report |
| 20.0 | 10 May 2009 | SC 07 Bad Neuenahr | H | 3:0 (3:0) | 1021.0 | Report |
| 21.0 | 17 May 2009 | 1. FFC Frankfurt | A | 1:2 (0:0) | 2460.0 | Report |
| 22.0 | 24 May 2009 | VfL Wolfsburg | H | 3:0 (1:0) | 2516.0 | Report |
Question:
Which match did FCR 2001 Duisburg participate as the opponent?
Answer:
21.0