Petra Kvitova has now won back-to-back titles following her success in St PetersburgPetra Kvitova has now won back-to-back titles following her success in St Petersburg (AFP Photo/KARIM JAAFAR)
Kvitova overcame an awful start which saw her lose the first five games to eventually triumph 3-6, 6-3, 6-4.
It is the first time Kvitova has been ranked among the world's elite since a horrific knife attack at her home in December 2016 left her with an injured hand.
"It feels great, it's a beautiful trophy," she said. "It took a while to have it. Today, it was a big fight."
Asked about being back in the top 10, Kvitova replied: "I remember sometime last year when I was asked about this, I couldn't even dream of it," she said. "It's a very special feeling to be back."
Questioned if it felt more special because of the circumstances of her comeback, she added: "It's something that's amazing, let's say. I couldn't really wish for more."
The win in Doha is the Czech star's second title of the season and 22nd career tournament victory.
It also extended her current winning streak to 13 matches, just one short of her career record.
She also beat four players in the top 10 this week in Doha, including world number one Caroline Wozniacki, to take the title.
Kvitova began the year ranked number 29 but was already on the rise after her win earlier this month in St Petersburg.
Her shaky start in Sunday's final extended to the second set, where Muguruza had break points in three separate service games.
She was unable to convert though and gradually Kvitova began to dominate and then broke the Spaniard's serve to edge ahead 4-2.
The third set followed a similar pattern, with Muguruza still having chances and even failing to take three break points in the fourth game of the decider.
It proved to be fatal as Kvitova not only held her serve but immediately broke the Spaniard's to take a lead in the match for the first time - an advantage she never relinquished.
In total, Kvitova faced 11 break points, but only lost her serve in the first set.
Muguruza -- who had an extra day to prepare for the final after receiving a bye in the semi-final -- finished the game with heavy strapping on her left knee, which she said was down to a "weird movement" but was hopeful there was no serious problem.
"I think I had a lot of break points and I didn't convert them," said Muguruza.
"I think also because she came out with all those winners. But yeah, I think if I would have got one of those break points it would be different."
Despite the defeat, Muguruza will move up one position in the rankings, making her the world number three.