Kang Min-hyuk (left) and Seo Seung-jae of South Korea pose with their gold medals from the men's doubles at the Badminton World Federation World Championships at the Royal Arena in Copenhagen on Sunday. (EPA-Yonhap)

The South Korean badminton duo of Seo Seung-jae and Kang Min-hyuk have struck gold in the men's doubles at the world championships in Denmark, giving their country a record title haul.

Seo and Kang, world No. 6, rallied to defeat 11th-ranked Kim Astrup and Anders Skaarup Rasmussen of Denmark 14-21, 21-15, 21-17 for the men's doubles crown at the Badminton World Federation World Championships in Copenhagen on Sunday (local time).

Seo and Kang are the first South Korean men's doubles team to win a world title since 2014.

Earlier Sunday on the same court at the Royal Arena, Seo had teamed up with Chae Yu-jung for the mixed doubles gold medal. The men's doubles title made Seo just the third South Korean player to win two gold medals at a single world championship.

The men's doubles gold was South Korea's third title on Sunday, with world No. 1 An Se-young having won the women's singles gold medal earlier. This represents South Korea's biggest gold medal haul at a single world championship in the event's 46-year history. South Korea previously won two titles each in 1985, 1991 and 1999.

In Copenhagen, South Korea also won bronze in the women's doubles, with Kim So-yeong and Kong Hee-yong finishing third following their semifinal loss to Apriyani Rahayu and Siti Fadia Silva Ramadhanti of Indonesia.

These medal-grabbing performances bode well for South Korea's prospects at the Asian Games beginning next month in Hangzhou, China. At the previous Asian Games in 2018, South Korea failed to win any medals in badminton, the first such occurrence since 1978.

With a partisan crowd behind them in the men's doubles final, Astrup and Rasmussen took the first game over Seo and Kang with relative ease. The Danish duo went up 8-2 early, and the South Korean team never once led, despite tying the score at 9-9 at one point.

Kang's winner got South Korea within three at 16-13, but then Denmark scored three quick points with Rasmussen's winner and consecutive errors by Kang and Seo. The home team closed out the game 21-14.

Seo and Kang looked to be a different team in the second game. They went up 5-2 early and overcame some dicey moments in the latter part to level the match at 1-1.

Seo and Kang went down 15-14 after Seo hit a return into the net but then they picked up seven straight points to win the game 21-15, with both Seo and Kang unleashing smash winners and Rasmussen sending multiple returns long and wide.

The teams traded points early in the third game. Denmark led 4-2 and then saw South Korea reel off five consecutive points, with Kang recording three winners during that rally.

A seesaw battle ensued, as the teams traded hard smashes and delicate drop shots.

Kang stepped up his game down the stretch. He displayed some soft touch with a deceptive drop shot to put South Korea up 16-13. Kang put down a winner to make it 18-15 South Korea after he and his partner put the Danes on the ropes.

With South Korea leading 19-17, Astrup's return went wide to put Seo and Kang on the brink of the title. Seo sealed the deal with a forehand winner.

"I can't believe I've won two world titles today," Seo said in an on-court interview after the medal ceremony. "It's incredible to enjoy a day like this."

Asked about the heavily pro-Denmark crowd, Kang said: "I am sorry that I let these people down, but this is such an important moment for my career. I feel really happy today."

In the mixed doubles final, Seo and Chae beat the top-ranked team from China, Zheng Siwei and Huang Yaqiong, 21-17, 10-21, 21-18.

Seo and Chae, world No. 5, became the first South Korean mixed doubles team to win a world title in 20 years.

For the women's singles title, An Se-young knocked off world No. 6 and 2016 Olympic champion Carolina Marin of Spain, 21-12, 21-10. (Yonhap)