Park will face Midori Yoneyama in the finals. Yoneyama won the last two holes of her match against Hee-Won Han to square the contest and then earned her ticket into the finals with a victory on the 19th hole.
This event featured a 32-player field with 16 golfers representing both the LPGA Tour and the Japan LPGA Tour. Golfers were seeded by their position on their respective tour's money list with the higher-ranked players meeting the lower-ranked players from the opposing tour in the first round.
This final match is an unexpected pairing as Park was seeded 12th on the LPGA Tour side and Yoneyama was ranked 14th for the JLPGA. In last year's final, it was a stark contrast as Annika Sorenstam met Se Ri Pak in a battle of the best players from ladies' golf.
Park dropped the first hole to Koch but that was one of the few speed bumps for the 23-year-old Korean. The two halved the second hole but Park rattled off four straight wins, starting at the par-5 third. Koch and Park halved the par-3 seventh but Park won the last two holes on the front side to take a 5-up lead into the second nine.
Koch won the 10th to momentarily cut the lead but Park responded by taking the 11th. Koch once again tried to close the gap when she was victorious on the 12th but after Park won the 14th hole, the match was over and Park advanced to the finals.
Yoneyama and Han were even through the first five holes before Han captured the par-5 sixth. Han won the next par-5, the 10th, to establish a 2-up advantage but Yoneyama countered late in the back nine.
Yoneyama and Han halved the first six holes on the second nine but Yoneyama had fight left in her. Yoneyama was 2-down but chipped away with a win on the par-5 17th and made it two in a row with a win on the 18th.
Yoneyama captured the first extra hole to earn her place in the final match.
There will be an 18-hole final on Sunday as well as a consolation match between Koch and Han for third place.
Results from the Cisco World Ladies Match Play Championship