The 22-year-old breezed to a straight-sets victory – 6-1 6-0 – needing less than an hour to beat her American opponent in a rain-delayed final in Cancún, Mexico.
The win means Świątek replaces Aryna Sabalenka as the world No. 1, having conceded the position at this year’s US Open.
“Coming back to world number one, it’s a dream come true, for sure,” Swiatek told reporters after winning her first WTA Finals title.
“I would say I wasn’t expecting that right now, this season. I was hoping that maybe next year is going to be my year, but it seems like you know, just working hard and focusing on the right things at the end worked. So I’m really happy.”
Since her last-16 defeat at the US Open, Świątek has won 12 out of the 13 matches she’s played, picking up titles at the China Open and now Cancún.