By FOX Sports staff
The Armed Forces, runners-up last season, fell behind at the Selayang Stadium after just three minutes when Togaba Kontiwa Komlan opened the scoring for the visitors, although parity was restored in the 14th minute when Fazrul Hazli scored an own-goal.
However, Togaba netted again in the 21st minute to restore Sime Darby's advantage, before Hadzirun Hamid struck to make it 3-1 on the half-hour mark.
A minute after halftime, the game looked to be over after Fazrul added a fourth for the visitors, but Irwan Fadzli Idrus netted in the 57th minute to keep ATM's hopes of a stunning comeback alive.
15 minutes from time, the deficit was reduced further when Venice Elphi scored the hosts' third but it proved to be too little too late as their opponents held on for all three points.
Elsewhere in the group, 32-time champions Selangor were also unable to get their campaign off to a winning start as they were held to a 0-0 draw at Johor.
There was another shock result in Group B as PKNS FC handed Darul Takzim a 2-0 defeat at the Shah Alam Stadium.
Liberian striker Patrick Ronaldinho Wleh fired the Selangor-based side ahead in the 16th minute, before adding a second four minutes before the hour mark to kill off the contest.
To make matters worse, Harimau Selatan were reduced to ten men five minutes later when goalkeeper Al-Hafiz Hamzah was sent off for handling the ball outside the area.
PKNS are joined at the top of the group by T-Team, who beat FELDA United 1-0 thanks to a 48th-minute winner from George Boateng.
Recently-relegated Negeri Sembilan gave their fans something to cheer as they moved to the top of Group C with an impressive 2-0 win over Terengganu at the Sultan Ismail Nasiruddin Shah Stadium.
Fabio Leandro Barbosa broke the deadlock four minutes before the break to put the visitors in front, before S. Sivanesan wrapped things up by netting a second in the 53rd minute.
Defending champions Kelantan had to settle for a point at the Darulmakmur Stadium as they were held to a 1-1 draw by Pahang.
After taking a ninth-minute lead through a Badhri Radzi strike, the Red Warriors were dealt a blow when Ahmad Fakri Saarani was sent off.
Nonetheless, Tok Gajah were also reduced to ten men after R. Surendran received his marching orders, but the hosts rallied and grabbed the equaliser five minutes from time when Damion Stewart popped up to score.
Perak claimed maximum points in Group D after coming from behind to beat Sarawak 2-1 at the Perak Stadium.
Joseph Kalang Tie netted in the 30th minute to hand the reigning Premier League champions the lead, only for Paulo Rangel level the scores eight minutes after the hour mark.
And with ten minutes on the clock, Rangel grabbed his second of the evening, which proved enough to hand his side the win.
Finally, Singaporean side LIONSXII were denied an opening-day victory as they were held to a 2-2 draw at home to a plucky Kedah outfit.
Singapore skipper Shahril Ishak had handed the LIONSXII the lead at the Jalan Besar Stadium with a close-range header in the 11th minute, but Alen Guc scored on the rebound to make it 1-1 seven minutes before the half-hour mark.
The hosts did reclaim the lead five minutes after the hour mark when substitute Shahfiq Ghani scored from a freekick but in the second minute of injury-time, Kedah were awarded a penalty when Shakir Hamzah felled Syafiq Ahmad inside the box, allowing Guc to step up and fire home the equaliser from 12 yards.
Wednesday's Malaysia Cup Results
Johor 0-0 Selangor
ATM 3-4 Sime Darby
PKNS FC 2-0 Darul Takzim
FELDA United 0-1 T-Team
Pahang 1-1 Kelantan
Terengganu 0-2 Negeri Sembilan
Perak 2-1 Sarawak
Image courtesy of ATM FA