Australian bad boy Nick Kyrgios may feel his decision to pull out of the Olympics was justified after he claimed his second ATP title by downing John Isner 7-6 (7-3) 7-6 (7-4) in the final of the Atlanta Open.

Top seed Isner was seeking a fourth consecutive title in the Georgia event on Sunday, but the tall American fell short in his historic quest in a battle of big servers.

Second seed Kyrgios overcame a love-40 deficit in his first service game, with both players holding serve throughout the match.

“Returning is very crucial against John,” said Kyrgios.

“That serve is world-class. It would have been a completely different story if he got me there.”

Kyrgios, 21, for all his undoubted talent, has made as many headlines for his off-court antics as for his tennis during his turbulent career.

He was in the headlines again recently when he pulled out of the Rio Olympics after a public spat with the Australian chef de mission Kitty Chiller, who said that some of Kyrgios’s social media posts suggested that “he doesn’t really understand what it means to be an Australian Olympian”.

Kyrgios responded to Chiller’s comments by announcing he would skip Rio.

The victory provisionally bumps the feisty 21-year-old up to a career-high ranking of 16, and will give him a crucial top-16 seeding at the US Open later this month.