In Bernd Stange's home and competitive debut as coach of the Singapore national football team, the Lions were beaten 0-2 by Oman at the Jalan Besar Stadium on Wednesday.
Singapore had began their Asian Cup qualifying Group A campaign with a 4-0 defeat by Jordan and they remain rooted to the bottom of the group after the two defeats.
The visitors took the lead after 15 minutes when midfielder Qasim Said fired a fierce angled drive into the bottom corner of the net after a neat passing move. Just before half-time, midfielder Eid Al-Farsi blasted a powerful low shot from 30 metres that zipped past Lions goalkeeper Izwan Mahbud.
Apart from an energetic opening 10 minutes, the Lions were disappointing had no shots on target. The closest they came was in the 30th minute, when Qiu Li's free kick curled wide of the post.