Portuguese forward Goncalo Ramos got things going with a fine finish in the first half and the visitor never looked back after that.

Nuno Mendes and Desire Doue added two in the second half to give Luis Enrique's side a vital three points, which takes them into the final play-off spot ahead of Thursday's (AEDT) matches.

The French side threatened from the outset, through Lee Kang-in, Achraf Hakimi and Bradley Barcola, though Salzburg goalkeeper Alexander Schlager managed to keep them at bay initially.

But it was Hakimi who laid on the opener for Ramos before Mendes smashed a left-footed shot home in the 72nd minute after being set up by Doue. Doue then got the third five minutes from time to add some gloss for the visitors.

Paris Saint-Germain is inside the play-off spots on goal difference, while Salzburg are four points back in 32nd with two matches remaining.