BERLIN -- Men's singles world No 1 Xu Xin had a fruitful day in doubles competitions at the 2019 ITTF German Open here on Saturday as the Chinese ace won both men's and mixed doubles titles.

In men's doubles final, Xu, paired with Liang Jingkun, beat Germany's Benedikt Duda and Qiu Dang 11-13, 11-9, 11-9, 11-9 to seal the victory, before he and Sun Yingsha prevailed over compatriots Wang Chuqin and Wang Manyu 12-10, 11-7, 5-11, 11-7 to stand on top of the podium.

Xu and Liang had high praise for each other. "Playing with Xu Xin gives me a lot of confidence. He also coached me during the match," Liang said.

"Liang Jingkun is the new generation and his every stroke is of very high quality. Every playing partner is different. When I am playing with them I try to adapt to their specialties," remarked Xu, who won the title in 2018 with Ma Long.

Xu and Liang were also victorious in men's singles on Sunday to continue their quest for another gold at the tournament. Xu will meet Jeoung Young-sik of South Korea in the semifinals, while Liang will face teammate Fan Zhendong, who fended off home favorite Timo Boll 14-12, 4-11, 11-7, 11-4, 11-8.

Elsewhere, No 4 seeds Jeon Ji-hee and Yang Hae-un of South Korea upset second-seeded Japan's Miyuu Kihara and Miyu Nagasaki 11-5, 4-11, 11-9, 11-7 to secure a gold and their eighth ITTF World Tour women's doubles title as a pair.

"I am very happy! We were prepared for a lot of difficulties before the match. In the third game we were behind for a long time and came back at the end (7-9). It wasn't easy," Jeon said.

In women's singles, China's Wang Yidi edged compatriot Wang Manyu 4-3 in the quarterfinals while Sun Yingsha triumphed in the other all-Chinese match-up over Chen Xingtong 4-2. Feng Tianwei of Singapore had a dramatic comeback win 4-3 trailing from three sets down to book a semifinal clash with Mima Ito of Japan.