Thailand's dream of playing at their third Fifa Women's World Cup finals was shattered at Hamilton's Waikato Stadium in New Zealand on Saturday.
The Chaba Kaew, despite a bright start, went 2-0 down to Cameroon in a play-off.
Both teams were aiming to qualify for a third successive World Cup finals, having competed in the 2015 and 2019 editions.
Cameroon will do battle with Portugal for a place in the finals after two goals from substitute Gabrielle Onguene earned them a victory over Thailand, who were eliminated.
The 2023 finals of the quadrennial tournament will be held in New Zealand and Australia from July 20 to Aug 20.
Thailand started in a confident mood but Cameroon slowly took charge of the proceedings.
The best scoring opportunity of the first half came when the Indomitable Lionesses' Charlene Meyong curled a right-foot shot only to hit the bar, while Jeannette Yango shot narrowly wide soon after the break.
The Thais struggled to break out of their own half as the match wore on but did have one near miss on the hour-mark when captain Nipawan Panyosuk found the side-netting with a free-kick from just outside the area.
But the Cameroonians always looked the more likely to find a winner, and so it proved, with Ajara Nchout's brilliant and unselfish set-up play on the right leaving Onguene with the simplest of side-foot finishes to break the deadlock with 11 minutes remaining and the super-sub struck again three minutes later.
There was drama deep into stoppage time when Cameroon goalkeeper Ange Bawou saw red for a dangerous challenge following a VAR review.
But while that forced forward Tatiana Ewodo Ekogo to take over in goal, with all the Africans' substitutes having already been made, Thailand were unable to find a way past the stand-in keeper.