Shortly after 10:15pm on Sunday two masked men entered the Bargain Booze store on Preston Road.
One of the men – who was carrying a knife – proceeded to threaten the shop keeper before grappling with him and becoming embroiled in a fight.
Seizing his opportunity while the shopkeeper was distracted, the second man went behind the counter and removed the drawer from the till.
The two offenders then fled the scene.
Police were then called shortly before 10:25pm and officers swiftly responded to carry out a search of the immediate area, with support from the police helicopter.
Two men, aged 36 and 43, were detained nearby and arrested on suspicion of robbery.
They remain in custody for questioning.
Detective Sergeant Nigel Rigby, of GMP’s Wigan District CID, said: “We currently have two men in custody as a result of some swift police work following an armed robbery at an off licence.
“Our investigation does not stop here and I want to appeal to anyone who may have information about this incident to please come forward and contact police.”
Anybody with information should contact police on 101 or the independent charity Crimestoppers, anonymously, on 0800 555 111.