The victim, Eleasar Pasague, 34, was shot with a caliber .45 automatic pistol in the abdomen.
Doctors at the Potenciano General Hospital said Pasague survived because the bullet did not hit vital organs.
The messenger is now listed in stable condition at the said hospital.
Pasague was delivering $15,000 cash (roughly P800,000) to a client when his black Suzuki motorcycle with license plate PR 5260 was blocked by the suspects on two motorcycles below the underpass of EDSA Crossing at about 3:30 p.m.
The suspects, all wearing helmets, initially ordered Pasague to stop, but he refused.
After blocking his path, one of the suspects grabbed the money.
Before escaping toward Makati City, another suspect took out a handgun and shot Pasague at point-blank range.
The messenger was crawling in pain on the pavement when a passing GMA-7 vehicle came to his aid and rushed him to a nearby hospital.
Pasague claimed that the four suspects were the same men who held him up a few months ago along Benitez street in Greenhills, San Juan.
SPO3 Jaime Masilang recovered a spent shell from a caliber .45 some five meters from the victim’s motorcycle.
Mandaluyong police officials have coordinated with Superintendent Rodelio Jocson, San Juan police chief, for the speedy arrest of the suspects.