Frenchman Gael Monfils has claimed his first ATP Tour title since February 2014 after beating veteran Ivo Karlovic in the Citi Open final in Washington.

He stopped the 37-year-old Karlovic from becoming the oldest man since 1973 to win ATP singles tournaments in consecutive weeks.

The 13th-seeded Croatian had won all 53 of his service games in the tournament prior to being broken while serving for the championship at 5-4 in the second set.