"Today is our 50th National Day and we'd like to dedicate this victory to all Malaysians. The win was very important and I told players to focus on the match," said manager Ponniah Tamilselvan.
Bangladesh also found it easy in their opening encounter as they thrashed Thailand 13-0, their biggest win in any international match.
Malaysia, who finished fifth in the last edition of the Asia Cup at home in 2003, took time to settle down on a rainy morning and led 3-0 at half time before outplaying the Singaporeans in the second session.
Zulkifli Rejab, Azlon Misron and Chua Boonhuat scored two goals apiece, while Ismail Abu and Megat Azrafiq each struck once.
"It was a slow start, but we adapted better as the match progressed," Tamilselvan said.
"It was a bit difficult playing the opening match as the ground was slippery. We scored three goals in the last three minutes and it was good to
finish on a high note."
Rasel Mahmud led Bangladesh's goal-spree against Thailand with four goals. Mohammad Mamun scored three, followed by Mohammad Zahidul Islam and Mohammad Iqbal Nadir with two apiece. Mohammad Jahidbin Talib and Khondokar Hasan were the other scorers.
"We expected to win the opening match, but never thought the margin would be so big. Our aim now is to play good hockey against big teams," said Bangladesh manager Mohammad Yusuf Ali.
Three-time champions Pakistan, Japan, Hong Kong, Malaysia and Singapore are in Group A while Group B comprises two-time winners South Korea, defending champions India, China, Bangladesh, Sri Lanka and Thailand.
The top two teams from each group will advance to the semi-finals.

Copyright AFP (Agence France-Presse), 2007