The 29-year-old captured the mixed doubles title yesterday alongside Zhu Yuling and today added both the men's singles and men's doubles crowns.

He becomes only the second player to achieve the "triple crown" after South Korea's Jang Woojin did so at the Korean Open last year.

Xu met a surprising opponent in the singles final as Chinese Taipei's 17-year-old 16th seed Yun-ju Lin battled to the showpiece match at the Hokkaido Prefectural Sports Center.

The Chinese player proved too strong as he engineered a 11-9, 14-12, 8-11, 11-3, 11-8 victory.

In the doubles final Xu partnered with world number one Fan Zhendong to oust Germany's Benedikt Duda and Dang Qiu, 12-10, 11-9, 11-7.

The match saw the Chinese duo team up shortly after colliding in the semi-finals of the singles.

This clash went the distance but it was Xu, a team Olympic gold medallist at Rio 2016 and a 10-time world champion, who came through 5-11, 11-4, 11-7, 5-11, 6-11, 11-8, 11-3.

Lin defeated China's Sun Wen 6-11, 11-2, 11-4, 11-9, 11-4 in his last four outing.

China also won the women's singles and doubles finals today to ensure they left Sapporo with all five available titles.

Qualifier Sun Yingsha triumphed in the former as she beat number four seed and compariot Liu Shiwen 11-4, 11-9, 4-11, 6-11, 7-11, 11-8, 11-3 to clinch a second World Tour title and a second in Japan.

Sun saw off another Chinese player in Chen Meng in the semi-finals, 11-5, 8-11, 11-7, 14-12, 11-6.

Liu disappointed the home fans as she knocked out Japan's Miu Hirano 9-11, 11-5, 11-4, 11-3, 12-10 in the last four.

In the women's doubles, Liu and Chen, both defeated by Sun in the singles, saw off the challenge of the individual winner and Wang Manyu 11-9, 11-6, 7-11, 11-9.

The Japan Open is a World Tour Platinum competition.

The next World Tour competition is the Korea Open from July 4 to 7 in Busan.