Cho So-hyun scored twice, while Jang Sel-gi, Lee Mi-na and Lim Seon-joo were also on target as the South Koreans claimed the fifth and final spot, along with the semi-finalists, at the Women's Asian Cup in Jordan.
"Our players did a great job and an excellent performance which helped us qualify for the World Cup," said Yoon, who also led the side to the Round of 16 at the 2015 World Cup finals in Canada.
"Of course, it would have been much better if we had been in the semi-finals, but all my players gave 100 percent in all the matches and played very well throughout the tournament.
"This is not the end, there is now the World Cup. We have found some things we need to improve and from now on, we will try to prepare well for next year in France."
South Korea and the Philippines finished third in their respective groups at the eight-team Asian continental championship, which doubles up as the region's final qualifier for France 2019.
Japan, Australia, China and Thailand had already advanced by reaching the last four in Jordan, with the semi-finals of the Asian tournament taking place on Tuesday ahead of the title decider on Friday.
(Reporting by Michael Church; Editing by John O'Brien)
