Garewal and Aman Raj shot one-over 73 each and were tied 51st while Dwivedi carded four-over 76 to be tied 86th and was in danger of missing the cut.
American John Michael O'Toole exploded in the opening round by shooting a new course record of eight-under-par 64 to lead by one shot.
O'Toole, who claimed his breakthrough Asian Development Tour (ADT) victory in March, produced nine birdies against a lone bogey to sit atop the leaderboard while Australian Adam Blyth trails in second place at the Penang Golf Club.
ADT Order of Merit leader Pavit Tangkamolprasert of Thailand and Malaysia's Gavin Green, who is chasing for a Rio Olympics berth, were among those bunched in 16th position on 70s at the PGM Penang Championship, which is the Tour's second stop in Penang this season.