According to Luca Brancher, the master of stats you wonder about but probably can’t find, Karlovic was just the third 39-year-old since 1990 to reach an ATP quarterfinal when he did it Wednesday in Houston.
The others were Jimmy Connors and Tommy Haas.
Karlovic reached the quarters at the NY Open in February. But that was a couple of weeks before his birthday, when he was a mere lad of 38.
And on Friday, with a win over an ailing Nick Kyrgios, Karlovic became the oldest man since 1993 to reach an ATP Tour semifinal.