Bangkok: Thailand's women made their first ever Uber Cup final on Friday after a stunning 3-2 upset of defending champions China.
In the men's Thomas Cup semis held the same day, powerhouses Japan and China advanced to the finals.
But the women's win captured the attention of the crowd and sets up an unlikely showdown between underdog Thailand and Japan on Saturday after the top seed defeated Korea 3-1 earlier in the day.
Thai player Busanan Ongbamrungphan was once again the star, as she confidently dispatched Olympic champion Li Xuerui " who was returning from injury " 21-11, 21-9 in the last game.
"Finally we did it, I never expected that today would really come," Busanan told reporters afterwards.
"It's lucky that the event was held in our country. I'm proud that once in my lifetime I played at home and have made people in my country happy," she added.
Thailand's victory also meant that China's women would not be going to the finals of the cup for the first time since the team started playing in 1984, according to the Badminton World Federation.
In the Uber Cup, Japan are the favourites going into the final, but the Thai win sparked jubilant on-court celebrations, hugs and ended a see-sawing matchup with tournament leader China.
World No 4 Ratchanok Intanon won the first singles game, grinding out a 15-21, 21-9, 21-14 win over China's Chen Yufei, who is ranked one place behind her.
With crowds shouting "Thailand! Thailand!" Ratchanok hit smash after smash to come back after losing the first game to win two in a row.
Thailand lost the first doubles, but singles shuttler Nitchaon Jindapol clawed her way back from a set down to beat Gao Fangjie in another thriller that had the crowd on their feet.
The second doubles went to China levelling up at 2-2, leaving Thai hopes pinned on Busanan, just as on Thursday when she performed under pressure to clinch a victory against Indonesia.
Japan had an easier time against South Korea in their Uber Cup semi, with doubles pair Misaki Matsutomo and Ayaka Takahashi securing their spot in the final.
World No 2 Akane Yamaguchi got the team off to a flying start, easing to a 21-10, 21-13 win against South Korea's Sung Ji-hyun, while Nozomi Okuhara dispatched Lee Jang-mi 21-9, 21-15 after South Korea had levelled at 1-1 with the first doubles.
Japanese World No 9 Okuhara has yet to lose in this year's biennial Uber Cup.
"I think it will be a tough battle whoever I face tomorrow," she told reporters afterwards as Thailand and China were still doing battle on court.
The tournament is played alongside the men's Thomas Cup, whose semis were held later on Friday, with China, Japan, Indonesia and Denmark all hoping to move forward.
Returning champions Denmark were back to attempt a repeat with World No 1 Viktor Axelsen leading the team. But Axelsen got the team off to a slow start against Japanese star Momota Kento, losing 21-17, 21-9.
The two national squads were tied at two wins apiece until Japan's Kanta Tsuneyama secured the final victory 21-18, 21-11 against Denmark's Jan O Jorgensen.
China has fielded an all-star cast of players as they seek to regain a title lost on home soil two years ago, going one step further by handily beating Indonesia 3-1 to advance.
China's Olympic champion Chen Long is joined by this year's All England champion Shi Yuqi " and the player he conquered in the final, Lin Dan.