The 26-year-old triumphed 6-3, 7-5 at the Lindner Family Tennis Center in Ohio, securing his biggest career win to date.  

Dimitrov broke once in each set to beat Kyrgios, who was also attempting to win his first Masters 1000 title.

With the pair level at 5-5 in the second set, Kyrgios posted his fourth double fault of the match on deuce before firing a wayward forehand over the baseline.

Dimitrov then served out to clinch his seventh career title as he prepares for the US Open, due to begin on August 28.

"In the big picture, it means a lot to me," Dimitrov, who went through the entire tournament without dropping a set, was reported as saying by BBC Sport.

"I'm pretty confident after that.

"This is what I've been practising for.

"I'm going to enjoy it for a day or two but then it's back to the routine and prepare for the US Open."

In the women's final, Wimbledon champion Garbiñe Muguruza of Spain thrashed world number two Simona Halep of Romania 6-1, 6-0.

Muguruza triumphed in just 57 minutes, denying her opponent a place at the top of the world rankings in the process.

Halep had reached the final without dropping a set, but she struggled to make an impact on today’s contest with 20 unforced errors.

Muguruza will start among the favourites for the US Open, where she will be bidding to claim a third Grand Slam title. 

"It doesn't always happen that you win a tournament and then go ahead and win a Grand Slam, but I'm happy to have the confidence - it beats not having it," said the 2016 French Open champion.

Czech Republic’s Karolína Plíšková, who lost to Muguruza in the semi-finals, will remain as the world number one.  

She has a five-point lead over Halep, while Muguruza has moved up to third spot.