The three-time Olympic silver medalist lost his final group match to Son yesterday but exacted revenge to book his place in the final, beating the South Korean 21-17, 21-11 at the Hamdan Sports Complex.

Both games were close in the early stages with the lead often changing hands in the United Arab Emirates city.

However, Lee, who won the Hong Kong Super Series title in November, put a large gap between himself and 2017 World Championship bronze medalist Son towards the end of each game.

Thirty-five-year-old Lee will now face Denmark's world champion Viktor Axelsen who, despite being seeded eighth prior to the tournament, beat third seed Shi Yuqi of China 21-12, 21-8.

The women's singles final will be contested between tournament favourite Akane Yamaguchi of Japan and fourth seed PV Sindhu from India.

This will be the second time the pair have met in a matter of days following their group stage match earlier in the tournament, in which Sindhu came out on top.

Yamaguchi's semi-final against Thailand's Ratchanok Intanon started badly as she lost the first game 21-17.

However, the number one seed thrashed her opponent 21-12 in the second to take it to a deciding third.

The final game was a much closer affair with the lead changing hands on several occasions.

Eventually, it was Yamaguchi who secured her place in the final with a 21-19 victory.

Sindhu's semi-final against seventh seed Chen Yufei of China was a much simpler affair as the Rio 2016 silver medallist won by a score of 21-15, 21-18.

The men's doubles event saw tournament favourites and recent Hong Kong Open champions Marcus Fernaldi Gideon and Kevin Sanjaya Sukamuljo of Singapore advance to the final following a close match against fifth seeded Japanese pairing Takeshi Kamura and Keigo Sonoda.

The Singaporeans were unstoppable in the first game as they ran out 21-10 winners.

Kamura and Sonoda then fought back well to take a close second game 21-18, meaning a third-game decider was required.

However, the Japanese duo could not shift the momentum of the match in their favour as Gideon and Sukamuljo lived up to their number one seeding to win the final game 21-16, ensuring their place in the final.

They will now face fourth seeds Liu Cheng and Zhang Nan of China, who managed to pull off a victory against second seeded pairing Mathias Boe and Carsten Mogensen of Denmark, beating them 21-17, 21-16.

The women's doubles final will be an all-Japanese affair with top seeds Shiho Tanaka and Koharu Yonemoto facing second seeds Yuki Fukushima and Sayaka Hirota.

Tanaka and Yonemoto beat Kamilla Rytter Juhl and Christinna Pedersen of Denmark 21-19, 21-19 in their semi-final and, although the scoreline suggests it was a close game, the Danish pair were only ahead once throughout the entire match.

Second seeds Fukushima and Hirota came through even more comfortably, dispatching seventh seed Chinese pairing Huang Yaqiong and Yu Xiaohan 21-13, 21-14.

The first mixed doubles semi-final of the day saw a shock result as fourth seeds Tang Chun Man and Tse Ying Suet of Hong Kong knocked out second seed pairing Wang Yilu and Huang Dongping from China to book their place in tomorrow's final.

It looked like the Chinese pair would make easy work of Chun and Ying following a 21-18 win in the first game, but the underdogs staged a superb comeback to take the next two games 21-18 and 21-17 respectively.

They will now face Chinese first seeded pair Zheng Siwei and Chen Qingchen in the final after they overcame Liliyana Natsir and Tontowi Ahmad of Singapore by a score of 21-12, 21-17, which, at just 38 minutes, was the shortest match of the day.

The Chinese duo, who won the 2015 BWF World Youth Championships, were briefly in trouble in the first game as they went 6-2 down to their third seed opponents.

However, they recovered magnificently to take ten consecutive points on the way to winning the first game.

Natsir and Ahmad put up a decent fight in what was to be the final game of the match, but 2017 World Championship silver medalists Siwei and Qingchen rallied back to win the game 21-17.

The finals at the season-ending event will be played tomorrow.