| Ivan Dodig CRO | - | D. Istomin | 6-3 | 6-4 | | | | 1st | 18 Jun 13 | AEGON International - Eastbourne | Grass |
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| Igor Sijsling NED | - | D. Istomin (14) | 7-64 | 6-1 | | | | 2nd | 13 Jun 13 | AEGON Championships - London | Grass |
| D. Istomin (14) | - | Andrey Kuznetsov RUS | 7-62 | 7-63 | | | | 1st | 11 Jun 13 |
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| Nikolay Davydenko RUS | - | D. Istomin | 6-4 | 7-5 | 6-2 | | | 2nd | 31 May 13 | French Open - Paris | Clay |
| D. Istomin | - | Florian Mayer GER (28) | 4-6 | 6-3 | 7-5 | Ret. | | 1st | 28 May 13 |
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| Richard Berankis LTU | - | D. Istomin (8) | 6-2 | 6-2 | | | | 1st | 19 May 13 | Open de Nice Cote d'Azur - Nice | Clay |
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| Tomas Berdych CZE (6) | - | D. Istomin | 6-4 | 6-0 | | | | 2nd | 14 May 13 | Internazionali BNL d'Italia - Rome | Clay |
| D. Istomin | - | John Isner USA | 5-7 | 7-65 | 6-3 | | | 1st | 12 May 13 |
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| David Ferrer ESP (4) | - | D. Istomin | 7-5 | 6-2 | | | | 2nd | 08 May 13 | Mutua Madrid Open - Madrid | Clay |
| D. Istomin | - | Xavier Malisse BEL (q) | 6-3 | 6-2 | | | | 1st | 06 May 13 |
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| Gastao Elias POR (WC) | - | D. Istomin | 3-6 | 6-1 | 6-4 | | | 2nd | 02 May 13 | Portugal Open - Oeiras | Clay |
| D. Istomin | - | Evgeny Donskoy RUS | 2-6 | 7-66 | 6-4 | | | 1st | 29 Apr 13 |
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| Dmitry Tursunov RUS (q) | - | D. Istomin | 6-3 | 6-4 | | | | 1st | 22 Apr 13 | Barcelona Open BancSabadell | Clay |
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| S. Wawrinka SUI (13) | - | D. Istomin | 6-3 | 7-5 | | | | 1st | 16 Apr 13 | Monte-Carlo Rolex Masters | Clay |
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| Bernard Tomic AUS | - | D. Istomin | 4-6 | 6-2 | 6-2 | 6-3 | | r4 | 07 Apr 13 | Davis Cup, Group I, 2R, UZB-AUS 1-3 | Clay |
| D. Istomin | - | Marinko Matosevic AUS | 6-4 | 7-61 | 3-6 | 6-4 | | r2 | 05 Apr 13 |
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| D. G.-Traver ESP | - | D. Istomin | 6-2 | 6-4 | | | | 1st | 21 Mar 13 | Sony Open Tennis - Miami | Hard |
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| Jurgen Melzer AUT (5) | - | D. Istomin (3) | 6-1 | 3-6 | 7-5 | | | 1/4 | 15 Mar 13 | Dallas Challenger | Hard |
| D. Istomin (3) | - | Lukas Lacko SVK | 7-5 | 6-3 | | | | 2nd | 14 Mar 13 |
| D. Istomin (3) | - | Tim Smyczek USA | 7-63 | 7-64 | | | | 1st | 12 Mar 13 |
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| Roger Federer SUI (2) | - | D. Istomin | 6-2 | 6-3 | | | | 2nd | 09 Mar 13 | BNP Paribas Open - Indian Wells | Hard |
| D. Istomin | - | Vasek Pospisil CAN (q) | 7-65 | 6-3 | | | | 1st | 07 Mar 13 |
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| Tommy Haas GER (2) | - | D. Istomin | 6-4 | 6-1 | | | | 2nd | 28 Feb 13 | Delray Beach Int. Tennis Camps. | Hard |
| D. Istomin | - | Benjamin Becker GER | 6-73 | 6-4 | 7-5 | | | 1st | 26 Feb 13 |
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| Feliciano Lopez ESP | - | D. Istomin | 6-2 | 3-6 | 6-3 | | | 1/2 | 23 Feb 13 | U.S. National Indoor Tennis Camps. - Memphis | I.hard |
| D. Istomin | - | Michael Russell USA (LL) | 6-4 | 7-65 | | | | 1/4 | 22 Feb 13 |
| D. Istomin | - | Lleyton Hewitt AUS | 6-1 | 6-2 | | | | 2nd | 21 Feb 13 |
| D. Istomin | - | John Isner USA (3) | 6-4 | 6-3 | | | | 1st | 19 Feb 13 |
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| Milos Raonic CAN (1) | - | D. Istomin (6) | 7-60 | 6-3 | | | | 1/4 | 15 Feb 13 | SAP Open - San Jose | I.hard |
| D. Istomin (6) | - | Benjamin Becker GER | 6-3 | 6-75 | 6-2 | | | 2nd | 14 Feb 13 |
| D. Istomin (6) | - | Ryan Sweeting USA (q) | 6-3 | 6-4 | | | | 1st | 12 Feb 13 |
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| D. Istomin | - | Di Wu CHN | 4-6 | 4-6 | 7-64 | 7-5 | 6-2 | r1 | 01 Feb 13 | Davis Cup, Group I, 1R, UZB-CHN 4-1 | Clay |
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| Andreas Seppi ITA (21) | - | D. Istomin | 7-64 | 5-7 | 6-73 | 7-63 | 6-2 | 2nd | 17 Jan 13 | Australian Open - Melbourne | Hard |
| D. Istomin | - | Igor Sijsling NED | 4-6 | 6-3 | 6-4 | 6-2 | | 1st | 15 Jan 13 |
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| Kevin Anderson RSA | - | D. Istomin | 6-4 | 6-3 | | | | 1/4 | 10 Jan 13 | Apia International - Sydney | Hard |
| D. Istomin | - | Fernando Verdasco ESP (4) | 6-3 | 6-3 | | | | 2nd | 09 Jan 13 |
| D. Istomin | - | James Duckworth AUS (WC) | 6-74 | 6-4 | 7-63 | | | 1st | 07 Jan 13 |
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| Andy Murray GBR (1) | - | D. Istomin | 6-4 | 7-63 | | | | 1/4 | 04 Jan 13 | Brisbane International - Brisbane | Hard |
| D. Istomin | - | Lleyton Hewitt AUS (WC) | 7-5 | 7-5 | | | | 2nd | 03 Jan 13 |
| D. Istomin | - | Martin Klizan SVK (8) | 6-1 | 6-2 | | | | 1st | 01 Jan 13 |