"I feel like I reached my best level of tennis, even if I had a long break before this tournament and I felt dead after the first day".
"My opponent has already six hours at the hotel resting, and I just finished the match and I'm doing now these (interviews)", Halep said at 9 p.m. local time (0100 GMT).
The world's top-ranked player defeated third-seeded Sloane Stephens 7-6 (6), 3-6, 6-4 in a see-saw battle that featured 15 service breaks - eight for Stephens, seven for Halep - at a steaming hot IGA Stadium on Sunday.
Spaniard Carolina Garcia, the No.6 seed, was combative in the first set before Halep secured a crucial break to win the opener 7-5.More news: McDonald's McGold Card Offers Contest Winner Free Food For Life
The 15th-seeded Barty won 80% of her first serve points and broke Bertens four times as she cruised to victory.
Next up for Halep is Australian Barty, who strolled to a 6-3 6-1 win over Kiki Bertens in their quarterfinal match earlier in the day.
Halep won her third title of the year and 18th overall.
It was a repeat of this year's French Open final in which Halep beat Stephens in three sets, but she said this one was even better. I thought she played well.More news: 3.3-Inch Palm Smartphone Heading to Verizon
"Obviously I'm sad I lost, but losing to the number one player isn't too bad. Yeah, it's disappointing, but I think this will help me moving forward, getting ready to go into (Cincinnati) and the U.S. Open".
A large Romanian contingent waving red and yellow flags chanted Halep's name between points.
The French Open champion showed no signs of fatigue following her marathon three-set win over Anastasia Pavlyuchenkova on Wednesday, running down balls to extend points and wear down the slower Garcia.
Halep broke the third-seeded Stephens with a crosscourt victor to take a 5-4 lead and serve for the set.More news: Iran denounces Trump's tariffs targeting Turkey
Stephens led throughout the second set, breaking Halep twice, but the Romanian took control of the third set, turning a break into a 5-2 advantage. I got better than the last final we played.