The 20-year-old Australian gave the first indication he is heading for a major breakthrough by claiming the Marseille title, beating former U.S. Open champion Marin Cilic 6-2 7-6 in the final Sunday.
It completed a stunning week for Kyrgios at the hard court tournament in southern France, having beaten two players in the world top 10 and a grand slam champion to lift the trophy.
10th-ranked Frenchman Richard Gasquet and world number eight Tomas Berdych fell victim to the big-serving young gun before he saw off fourth seed Cilic with another impressive display.
His straight sets victory over Berdych was revenge for a third round defeat in his home grand slam in Australia last month, while he had lost his previous encounter with Cilic in 2013.
Read: Krygios 'circus shorts' cause a stir
Two breaks of service in the first set saw Kyrgios make early inroads in the final. The second set was closer with no breaks of service, but Kyrgios closed out the tiebreaker 7-3 with his 17th ace to complete his triumph.
It was only his second tournament of the year after having to pull out of Rotterdam with injury and taking the title was a surprise.
"But I didn't really expect to win this title this week after having a couple of weeks off. But from the first round I started playing really well and just gained confidence as I kept winning matches," Kyrgios told the official ATP Tour website.
World number 41 Kyrgios first burst to prominence at Wimbledon in 2014 when he stunned Rafael Nadal on his way to the quarterfinals, leaving many to believe he would soon be challenging for grand slam titles.
Controversial incidents
But his career has stalled with only a quarterfinal appearance at the Australian Open in 2013 in the majors, while courting controversy in several incidents.
The most notorious led to a 28-day ban, suspended for sixth months, by the ATP Tour and a $10,000 fine after personal comments directed at opponent Stan Wawrinka in a 2015 Rogers Cup in Canada.
But with his aggressive style and massive serving, experts predict Kyrgios has a bright future and beaten opponent Cilic was clearly impressed.
"I think he played really, really well today. He served amazing. It was difficult also from the back of the court. I think he was returning well, making a lot of returns in the first set. I didn't adjust well enough on the balls that were coming back."
Kyrgios is the first player under the age of 21 to beat top 10 ranked opponents in consecutive matches since Juan Martin del Potro at the 2009 US Open.
Argentina's del Potro, who went on to claim the title, has been hard hit by a wrist injury in recent seasons, but made a successful return to the ATP tour in the tournament at Delray Beach in Florida.
He reached the last four, losing to American Sam Querrey 7-5 7-5 in Saturday night's semifinal, having beaten four opponents in impressive style without dropping a set.
But Nadal's miserable 2016 continued with a shock semifinal defeat in the clay court tournament in Rio which he won in 2014.
The Spanish top seed was upset 6-7 7-6 6-4 by Pablo Cuevas of Uruguay, denying him a 100th ATP Tour final appearance.
Rafael Nadal makes a rueful farewell after losing in the semifinals in Rio.
Cuevas won the crucial break in the third set of a marathon match to earn revenge for a quarterfinal defeat to Nadal last year.
It was the nine-time French Open champion's only defeat to a player ranked outside the world top 30 in a match on clay since 2005.
It followed a semifinal defeat on clay in Buenos Aires and a shock first round exit at the Australian Open to compatriot Fernando Verdasco.
"I fought until the end. I have to accept it and keep working to try to change the dynamic. That's what's happening today and I have to work hard to change it," was the verdict of the 29-year-old Nadal.
