Kyrgios has a highest ranking of 13 in October 2016 and went into the Washington tournament ranked 52nd
Australian Nick Kyrgios won his sixth ATP title with a 7-6 (8-6) 7-6 (7-4) victory over third seed Daniil Medvedev at the Citi Open in Washington.
Russian Medvedev, the world number 10, led 5-2 in the first set tie-break but after saving a set point, 24-year-old Kyrgios took it in 41 minutes.
Kyrgios, who will move back into the top 30 with his win, sent down his 17th ace to create two match points.
He needed only one as he wrapped up the match in an hour and 34 minutes.
The colourful Australian had beaten Medvedev, 23, in three sets in their only previous meeting, which came on the clay courts of Rome earlier this year.
It also improved his impressive record against top-10 players this year to 5-1.