Swiatek has won three Grand Slam titles in her careerWorld number one Iga Swiatek claimed her eighth title of 2022 by beating Donna Vekic 6-3 3-6 6-0 in the San Diego Open final.
The win was the 64th of the season for Poland's Swiatek, who has won the French Open and US Open this year.
Vekic, who had finished her rain-interrupted semi-final against American Danielle Collins earlier on in the day, pushed Swiatek but faded at the end.
"It was a really tight match and pretty long," Swiatek said.
"We felt the intensity for sure. At the end I wanted to be the one who played the last ball in."
Swiatek broke Croatia's Vekic, who has moved up to number 47 in the world rankings, in the sixth game and held twice to capture the first set.
Vekic, who will move up to 47 in the world rankings, broke her rival via a cross-court forehand to take 4-2 lead in the second before she held her serve twice to level.
Swiatek quickly took control in the decider and secured victory in the WTA 500 event after one hour and 47 minutes when Vekic double faulted.
"I wanted to go all in," Swiatek said.
"Knowing how well she can serve, I just wanted to be more loosened up on my return games - not think too much, use my intuition and fight for every ball."
