Scotland did it the hard way as they reached their first major tournament since 1998 after a 1-1 draw.
Ryan Christie,appeared to have sent Steve Clarke’s dominant side into Euro 2020 but Serbia scored with their first effort on target in the 90th minute.
However, the blow proved to be fleeting as Marshall saved from Aleksandar Mitrovic in the 10th penalty of the shoot-out.
It was almost even better too, but the Serbs’ late equaliser denied Scotland to win 1-0 in 90 minutes.
Christie gave Scotland a deserved 52nd-minute lead with an excellent strike from outside the box and Steve Clarke’s side had chances to give themselves an extra cushion.
They would regret not getting a second goal, despite looking comfortable for the vast majority of normal time.
Marshall was rarely troubled, the Scotland defence were resolute when they needed to be, the midfield composed and confident and Christie, John McGinn and Lyndon Dykes gave the home defence serious problems.
But Serbia put Scotland under some late aerial pressure and Luka Jovic headed home unchallenged following a corner 20 seconds before the 90-minute mark.
However, Scotland secured a 5-4 penalties triumph to set themselves up for two Hampden encounters against Croatia and Czech Republic and a Wembley clash with England at next summer’s delayed finals.