Both defending champions of the men's and women's singles events at badminton's OUE Singapore Open easily passed their first tests in their respective opening matches in the main draw on Wednesday.

Indonesia's Simon Santoso, who won the event last year as a qualifier, got through his first-round match against Malaysia's Mohamad Arif Abdul Latif 21-14, 21-14.

Santoso, the world No. 38 who also had to go through the qualifiers this year, will meet a far more formidable foe next in the second round, where he will play Denmark's world No. 6 Viktor Axelsen.

In the women's singles, two-time defending champion Wang Yihan stayed on course for a hat-trick of titles when she easily defeated Vietnam's Vu Thi Trang 21-13, 21-11 in less than 30 minutes.

Said the world No. 8 from China: "It was not too much of a problem for me even though I've never played her."

Wang next plays Zhang Beiwen, a Singaporean who now plays under the auspices of the United States. The latter defeated Hong Kong's Yip Pui Yin 21-18, 21-15.