Defending champion Sergio Garcia trailed on the opening day the SMBC Singapore Open on Thursday as he tried to shake off a sinus infection and an upset stomach.

Hung Chien-Yao of Taiwan grabbed the early lead with a five-under par 66 in the round which was halted by bad weather.

The 26-year-old, who welcomed a baby daughter in November, is chasing his first victory on the Asian Tour.

Miguel Tabuena, 24, of the Philippines was in second spot with a four-under par 67 after he missed a chance for the lead due to a bogey.

"My game's still pretty rusty," said Tabuena, who was tied with the Japanese duo of Yuta Ikeda, a multiple winner on home soil, and Yoshinori Fujimoto.

England's Matthew Fitzpatrick, playing his first Singapore Open, signed for a 68, along with Thailand's Jazz Janewattananond and Nicholas Fung of Malaysia.

Spanish and Ryder Cup star Garcia -- the tournament's defending champion -- was under the weather but managed to card a 69.

"I've had a little bit of a sinus infection these last couple of days, and a bit of an upset stomach this morning. But I think I played nicely, and the highest I can shoot," the 2017 Masters champion said.

"Obviously there were a couple of shots here and there where I was a little bit rusty, like this one on the last (ninth hole) for example, the second shot," added Garcia, 39.

"But other than that I felt like I played well. I gave myself a lot of chances and hit some good putts. I didn’t really make a lot, but the greens are tricky. They're very fast, and you have to be very aware of your speed, and unfortunately I lacked a little bit of speed in a couple of parts here and there."

Ryo Ishikawa, the prince of Japanese golf who has recovered from a serious back injury, was initially in top form until he hit two bogeys in the last three holes.

He is tied with playing partner Garcia.

Lightning halted play for over three hours in the afternoon at the Sentosa Golf Club and play was cut short again later due to fading light with 78 players still to complete the round.