Nick Kyrgios victorious at the Citi Open in Washington

Nick Kyrgios won his second ATP Tour title of the season with victory over Daniil Medvedev in the Citi Open final in Washington.

The Australian was at his exuberant best in a semi-final win over Stefanos Tsitsipas on Saturday and followed that up with a tight 7-6 (7-6) 7-6 (7-4) triumph against third seed Medvedev.

There were no break points for either man during the match, which came down to a couple of points in each tie-break.

Medvedev had the first set point in the opener as Kyrgios, who was struggling with back spasms, looked rather uncomfortable but the Australian saved it with one of 18 aces he served during the match.

Kyrgios again threw in an underarm serve and, as he has during the last three rounds, asked a member of crowd where he should serve on match point, duly finishing things off with an ace.

"It's amazing. Where I was six months ago, some of the things I was doing, to respond like this having incredible support, it's amazing," said Kyrgios after his victory.

I've proved to myself and a lot of people that have backed me that I still have it. It's been one of the best weeks of my life from a tennis perspective.

"I just wanted to clean myself up and have healthier habits," Kyrgios added, using his fingers to signal quotation marks around "clean".

"It's only the beginning and it showed this week by winning this tournament. I had the same routine every day. And I just felt I felt actually like a traditional tennis player this week.

"I feel like I've made major strides. I'm just going to take it one day at a time and hopefully I can continue on this new path."

Kyrgios, who also beat a host of top players to win the title in Acapulco in March, will now return to the world's top 30 and should be seeded at the US Open.

With a potential seeding comes the chance to avoid meeting another seeded player at Flushing Meadows until the third round or beyond.

Meanwhile, Dominic Thiem triumphed on his home soil as he won the Austria Open title in Kitzbuhel.

The world No 4 saved all six break points he faced to defeat Albert Ramos-Vinolas 7-6 (7-0) 6-1.

Diego Schwartzman claimed victory in the Los Cabos Open final in Mexico, winning 7-6 (6) 6-3 against Taylor Fritz to scoop this third career title.