Swiatek, back from injury and gearing up for her French Open title defense next month, and world No. 2 Sabalenka traded powerful baseline blows before Swiatek earned a second breakpoint at 4-3.
She whipped a superb forehand down the line to go 5-3 up before easily holding serve to clinch the first set on her second set point.
Swiatek, fit again following a rib injury that forced her to withdraw ahead of the Miami Open and Billie Jean King Cup qualifiers after she hurt herself during her run to the Indian Wells semifinals last month, broke her opponent again in the first game of the second set.
Sabalenka started to pile up unforced errors and struggled with her serve at 2-0 before firing a cross-court forehand to hold.
But she could not break Swiatek, who held serve at 5-4 to seal her second title of the year.
“I want to thank my team because it has been such an intense time. I am so happy we are making the right decisions,” Swiatek said, following her well-timed return from injury.
“It is a pretty exciting time. I will be coming back because I love this tournament.”
While Swiatek won it for a second consecutive time, it was Sabalenka’s third straight loss in the final in Stuttgart.
Information from Reuters was used in this report.
Iga Swiatek again sinks Aryna Sabalenka for Stuttgart title