Valenzuela downs top-seeded Vu on second day of LPGA Match-Play
The second day of round-robin play saw 16 players in the field of 64 mathematically eliminated with one more round of group matches to come on Friday.
They included China's Lin Xiyu, the highest-ranked player in her group, who suffered a second straight defeat with her 3&2 loss to Thailand's Pajaree Anannarukarn.
Valenzuela improved to 2-0 with her win over Vu, the highest-ranked player in the field at fourth in the world and winner of her first major title at the Chevron Championship last month.
Valenzuela trailed early, but won four holes in a five-hole span from the sixth through the 10th to take control.
"Very happy to walk away with a win," Valenzuela said. "I knew this was going to be a very tough match. Lilia is undoubtedly one of the best players in the world and made me work for the points.
"She definitely left some putts out there, and I did as well, so we kind of fought 'til the end," Valenzuela said.
Defending champion Ji Eun-hee, who had opened with a victory on Wednesday, also lost on Thursday, with Canadian Maddie Szeryk downing the South Korean 3&2.
Valenzuela was among 10 players to improve to 2-0, a group that also included American Ally Ewing - winner of the inaugural edition in 2021 - and 2022 runner-up Ayaka Furue of Japan.
Ewing beat Thailand's Jaravee Boonchant 3&2 while Furue beat American Stacy Lewis 4&2.
Three-time major winner Anna Nordqvist of Sweden notched her second-straight win, leading 4-up before holding on for a 1-up win over Lauren Coughlin.
Sweden's Maja Stark also won her second-straight match, downing Liu Yu of China 2&1.
Stark, 23, is playing the tournament at Shadow Creek for the first time, but her precise iron play saw her win five of the first seven holes to take control of her match.
Ireland's Leona Maguire had to battle back from 4-down to win her second straight, a 1-up victory over South Korean's Jenny Shin.
"I think you can have some really big wins if someone is just on fire, but you don't have to miss very much to find yourself in trouble out here," Maguire said.
"But at the same time, you can have those big seesaw matches where someone's up, someone is down - you can make a comeback."
