Faizal Shaari, who returned to the national squad after serving his six-month ban and service with the back-up squad, scored a penalty stroke and a field goal to hand Malaysia the crucial win.
The first quarter was shaky, as Malaysia and Pakistan both played bad hockey and the crowd were almost put to sleep,
However, when the rain came pouring and stopped the match for 10 minutes, Malaysia regrouped and came out looking fresh in attack -- winning three crucial points in their attempt to finish higher than three consecutive bronze medals in the ACT.
Coach Stephen van Huizen's men lived dangerously, and three goals after the second half breather is what separated them from Pakistan.
They face China today, in what is expected to be another three points in the bag.
"The rain came at the right moment and my players regrouped and put up a good fight in the opening match even though Pakistan are never easy to beat," said Van Huizen.
"Penalty corners are our strongest in this tournament, and we utilised those that came our way. As for Faizal his goals made the difference but there is still much work to be done form him before he becomes what he was in previous years," said Van Huizen.
And China?: "We expect another good match, and even though they are a new side, nothing can be taken for granted tomorrow (today)."
Malaysia, with six penalty corner flickers in their fold, won their first in the 12th minute but Razie Rahim's flick was blocked by the first runner and they were awarded a consecutive second.
This time, Razie was on target but the ball was deflected out for pusher Firhan Ashaari to knock in from close range for a 13th minute lead.
However Aleem Bilal, 23, and into his first International with the seniors, scored two penalty corner goals in the 18th and 34th minutes to put the pressure on the hosts.
It was then that the match was stopped for 10 minutes as the rain lashed heavier and flooded the pitch.
And after resumption, two consecutive rough tackles by Pakistan goalkeeper Imran Butt on youngster Aiman Nik Rosemi in the 36th, resulted in a penalty stroke after a video referral.
Faizal Shaari executed a low push from the spot, and Malaysia were level at 2-2 by the 37th minute.
Malaysia were presented with a golden opportunity when they won their fifth penalty corner in the 41st minute, and Shahril Saabah's attempt made it 3-2.
The fourth goal came off a botched sixth penalty corner under pouring rain, which was salvaged by a powerful hit to the top of the net by Faizal in the 60th minute, for his brace.
RESULTS: Malaysia 4 Pakistan 2, India 10 Japan 2.
FRIDAY: Pakistan v South Korea (6.30pm), Malaysia v China (8.30pm).
SATURDAY: India v South Korea (6.30pm), China v Japan (8.30pm).
P W D L F A Pts
INDIA 1 1 0 0 10 2 3
MALAYSIA 1 1 0 0 4 2 3
PAKISTAN 1 0 0 1 2 4 0
JAPAN 1 0 0 1 0 10 0
CHINA 0 0 0 0 0 0 0
S. KOREA 0 0 0 0 0 0 0