Ko won for the third time in her last four starts, which includes her Olympic gold medal that gave the 27-year-old from New Zealand enough points to qualify for the LPGA Hall of Fame.
It also includes another major in the Women's British Open, this one at St. Andrews.
"It's been pretty surreal," Ko said after her five-shot victory at the TPC River's Bend over Jeeno Thitikul, who closed with a 70 and simply couldn't keep up.
Lydia Ko won for the third time in her last four tournaments. (AP PHOTO)
Thitikul was two shots ahead after eight holes of the final round. Three holes later, the Thai was chasing the hottest player in women's golf.
Thitikul made bogey on the par-4 ninth. Ko made a 10-foot birdie putt on the 10th hole to tie for the lead, and then pulled ahead by two shots with a 12-foot eagle putt on the par-5 11th.
Ko seized control for good with a pair of two-shot swings — she made birdie and Thitikul made bogey on the 13th and 15th holes.
Thitikul two-putted for birdie on the par-5 closing hole to at least finish alone in second, one shot ahead of Haeran Ryu (67).
"It's just like insane — it's super insane. Her putter was on fire today," Thitikul said of playing alongside Ko.
"I respect her as like my older sister, as a legend, and also as my role model. It was such a really good experience watching her in my eyes on the same tee box, on the same greens, just like VIP seat."
Nelly Korda, the No. 1 player in women's golf who still has a comfortable lead in the Race to CME Globe with her six victories this year, had a 68 and tied for fifth, nine shots behind.
Ko, who finished at 23-under 265, now has 22 career LPGA victories. It was the fifth time she has at least three wins in the same season on the LPGA, her biggest year coming with five wins when she was 18 and reached No. 1 in the world.
Ko also won the season opener in Florida in January, but there were times early in the summer when she wondered if she would ever get the final victory needed for the LPGA Hall of Fame.
She took care of that with Olympic gold in Paris, won at St. Andrews for her third major and, after a three-week break, picked up as though nothing had changed.
"I had the most unbelievable three weeks in Europe. And now after having another three weeks off here, not entirely sure what it's going to be like," Ko said.
