| Australian Open | 01/19 04:50 | 25 | Andreas Seppi v Ivo Karlovic | 6-3,7-6,6-7,6-7,9-7 | |
| Australian Open | 01/17 02:20 | 24 | Ivo Karlovic v Yuichi Sugita | 7-6,6-7,7-5,4-6,12-10 | |
| Australian Open | 01/15 05:15 | 23 | Ivo Karlovic v Laslo Djere | 7-6,6-3,7-6 | |
| ATP Antwerp | 10/19 10:00 | 26 | [51] Ivo Karlovic v Stefanos Tsitsipas [122] | Retired | |
| ATP Antwerp | 10/16 12:55 | 25 | [51] Ivo Karlovic v Guido Pella [64] | 3-6,7-5,7-6 | |
| ATP Shanghai | 10/09 05:00 | 24 | [34] Feliciano Lopez v Ivo Karlovic [49] | 7-6,7-6 | |
| ATP Tokyo | 10/02 10:55 | 25 | [49] Ivo Karlovic v Matthew Ebden [139] | 4-6,3-6 | |
| US Open | 08/29 15:00 | 23 | [135] Bjorn Fratangelo v Ivo Karlovic [38] | 7-6,6-4,3-6,7-6 | |
| ATP Cincinnati | 08/17 22:55 | 26 | [23] Nick Kyrgios v Ivo Karlovic [44] | 4-6,7-6,6-3 | |
| ATP Cincinnati | 08/15 23:00 | 25 | [44] Ivo Karlovic v Jo-Wilfried Tsonga [12] | 6-4,7-6 | |
| ATP Cincinnati | 08/14 15:00 | 24 | [44] Ivo Karlovic v Jiri Vesely [52] | 6-3,3-6,7-5 | |
| ATP Los Cabos | 08/02 00:00 | 25 | [31] Ivo Karlovic v Quentin Halys [126] | 6-7,6-7 | |
| ATP Newport | 07/20 19:35 | 27 | [131] Peter Gojowczyk v Ivo Karlovic [25] | 7-6,6-7,7-6 | |
| ATP Newport | 07/19 15:00 | 26 | [178] Denis Kudla v Ivo Karlovic [25] | 4-6,4-6 | |
| Wimbledon | 07/03 15:10 | 23 | [23] Ivo Karlovic v Aljaz Bedene [58] | 7-6,6-7,7-6,6-7,6-8 | |
| ATP Halle | 06/20 16:00 | 25 | [24] Ivo Karlovic v Mikhail Youzhny [88] | 3-6,6-7 | |
| ATP Den Bosch | 06/18 12:30 | 29 | [24] Ivo Karlovic v Gilles Muller [28] | 6-7,6-7 | |
| ATP Den Bosch | 06/17 15:10 | 28 | [7] Marin Cilic v Ivo Karlovic [24] | 6-7,7-5,6-7 | |
| ATP Den Bosch | 06/16 11:05 | 27 | [24] Ivo Karlovic v Daniil Medvedev [65] | 6-4,6-4 | |
| ATP Den Bosch | 06/15 09:00 | 26 | [24] Ivo Karlovic v Stefan Kozlov [150] | 6-4,6-1 | |
| French Open | 05/31 10:50 | 24 | [24] Ivo Karlovic v Horacio Zeballos [65] | 6-7,6-7,3-6 | |
| French Open | 05/28 12:35 | 23 | [24] Ivo Karlovic v Stefanos Tsitsipas [202] | 7-6,7-5,6-4 | |
| ATP Rome | 05/16 08:00 | - | Ivo Karlovic v Tommy Haas | Cancelled | |
| ATP Madrid | 05/10 18:20 | 25 | [12] Grigor Dimitrov v Ivo Karlovic [22] | 6-3,7-5 | |
| ATP Madrid | 05/09 10:00 | 24 | [22] Ivo Karlovic v Roberto Bautista-Agut [21] | 7-6,6-7,7-6 | |
| ATP Budapest | 04/28 10:00 | 27 | [68] Aljaz Bedene v Ivo Karlovic [22] | 6-4,6-3 | |
| ATP Budapest | 04/26 12:10 | 26 | [90] Damir Dzumhur v Ivo Karlovic [22] | 1-6,6-3,4-6 | |
| ATP Miami | 03/27 20:15 | 25 | [16] Nick Kyrgios v Ivo Karlovic [21] | 6-4,6-7,7-6 | |
| ATP Miami | 03/25 21:20 | 24 | [68] Andrey Kuznetsov v Ivo Karlovic [21] | 6-7,1-6 | |
| ATP Indian Wells | 03/11 19:00 | 24 | [21] Ivo Karlovic v Yoshihito Nishioka [70] | 4-6,3-6 |