![Ivo Karlovic of Croatia returns a shot during his tennis match against John Isner of the United States during the U.S. Men's Clay Court Championships at River Oaks Country Club on Friday Ivo Karlovic of Croatia returns a shot during his tennis match against John Isner of the United States during the U.S. Men's Clay Court Championships at River Oaks Country Club on Friday](https://c8.alamy.com/comp/2P77NF4/ivo-karlovic-of-croatia-returns-a-shot-during-his-tennis-match-against-john-isner-of-the-united-states-during-the-us-mens-clay-court-championships-at-river-oaks-country-club-on-friday-april-8-2011-in-houston-texas-karlovic-won-7-6-2-6-7-2-7-6-9-ap-photoaaron-m-sprecher-2P77NF4.jpg)
Ivo Karlovic of Croatia returns a shot during his tennis match against John Isner of the United States during the U.S. Men's Clay Court Championships at River Oaks Country Club on Friday
![Ivo Karlovic becomes oldest ATP winner in 37 years with success in Rhode Island | Tennis News | Sky Sports Ivo Karlovic becomes oldest ATP winner in 37 years with success in Rhode Island | Tennis News | Sky Sports](https://e0.365dm.com/16/07/2048x1152/ivo-karlovic-backhand_3746700.jpg)
Ivo Karlovic becomes oldest ATP winner in 37 years with success in Rhode Island | Tennis News | Sky Sports
![French Open 2019: Ivo Karlovic and Feliciano Lopez serve up oldest match in French Open history - Eurosport French Open 2019: Ivo Karlovic and Feliciano Lopez serve up oldest match in French Open history - Eurosport](https://imgresizer.eurosport.com/unsafe/2560x1440/filters:format(jpeg)/origin-imgresizer.eurosport.com/2019/05/28/2599321-53885130-2560-1440.jpg)
French Open 2019: Ivo Karlovic and Feliciano Lopez serve up oldest match in French Open history - Eurosport
![Ivo Karlovic, of Croatia, serves to Andrey Rublev, of Russia, during the first round of the US Open tennis championships, Monday, Aug. 30, 2021, in New York. (AP Photo/John Minchillo Stock Photo - Ivo Karlovic, of Croatia, serves to Andrey Rublev, of Russia, during the first round of the US Open tennis championships, Monday, Aug. 30, 2021, in New York. (AP Photo/John Minchillo Stock Photo -](https://c8.alamy.com/comp/2MDPBNC/ivo-karlovic-of-croatia-serves-to-andrey-rublev-of-russia-during-the-first-round-of-the-us-open-tennis-championships-monday-aug-30-2021-in-new-york-ap-photojohn-minchillo-2MDPBNC.jpg)