The big-serving 6ft, 11in Croat, though, still holds the record as the oldest ATP Tour champion at 37-years, five months and eight days, which he set when he won the Los Cabos Open in August 2016.
That victory came just a month after he won the Hall of Fame Tennis Championships in Newport at the age of 37 years, four months and 11 days.
Victor Estrella and Roger Federer are joint-second on the list as they were both 36 years, six months and four days when they won their last title. In the case of Estrella, he won the Ecuador Open in 2017 while Federer won the Rotterdam Open in February this year.
Spaniard Feliciano Lopez is fourth on the back of his success at the Queen’s Club Championship last year while Fabrice Santoro from Italy completes the top five.
Andre Agassi comes in at seventh as he was 35 years, two months and 26 days when he won the Los Angeles Open in 2005 while Nicolas Mahut just makes it into the top 10 as he was 34 years, four months and 16 days at the time of his Rosmalen Grass Court Championships victory in 2016.
Top 10 ATP Tour trophy winners
1. Ivo Karlovic (Croatia) – 37 years, five months, eight days – Los Cabos 2016
2. Victor Estrella (Dominican Republic) – 36 years, six months, eight days – Quito 2017
2. Roger Federer (Switzerland)-36 years, six months, eight days – Rotterdam 2018
4. Feliciano Lopez (Spain) – 35 years, eight months, 29 days – London 2017
5. Fabrice Santoro (France) – 35 years six months, 29 days – Newport 2008
6. Tommy Haas (Germany) – 35 years, six months, 11 days – Vienna 2013
7. David Ferrer (Spain) – 35 years, three months, 15 days – Bastad 2017
8. Andre Agassi (United States) – 35 years, two months, 26 days – Los Angeles 2005
9. Paolo Lorenzi (Italy) – 34 years, seven months, three days – Kitzbuhel 2016
10. Nicolas Mahut (France) – 34 years, four months, 16 days – s-Hertogenbosch 2016
As for the all-time men’s record, Richard Pancho Gonzales leads the way as the American was 43 years, eight months and 28 days when he won the Des Moines title in 1972 while Australian Ken Rosewall (43 years, five days) sits second on the list on the back of his title in Los Angeles in 1971.
Karlovic is fifth on the all-time list.