It was always going to be a busy night for the Larne defenders against the class of the Red Star attackers, but they limited the visitors to very little in the opening half of the first period.
That was until VAR intervened and referee Rares George Vidican pointed to the spot following a brief look at the monitor where he deemed Tomas Cosgrove had handled the ball.
Bruno Duarte made no mistake from 12-yards and sent Rohan Ferguson the wrong way to find the bottom right-hand corner with a cool finish on 26 minutes.
Although the Serbian side continued to dominate proceedings, they couldn't find a way past the resolute Larne defence from open play.
That was until 10 minutes into the second half when Red Star doubled their lead through Kostov after some lovely work from substitute Osman Bukari down the right-hand side.
Red Star had their third 12 minutes later with a second strike from Bruno Duarte who found the bottom right-hand corner after a brilliant attacking move.
Substitute Cham put the icing on the cake for the visitors on 85 minutes with the pick of the bunch as he fired into the top right-hand corner from the edge of the box.