Charlton had to wait until midway through the opening period to create their first opportunity when Albie Morgan fired just wide after being picked out by Alfie Doughty.

Only a stunning reaction stop from Joseph Wollacott prevented Naby Sarr putting the hosts in front, with Sam Field's follow-up well blocked by a Forest Green defender.

Doughty's angled drive tested Wollacott immediately after the interval.

Chuks Aneke's close range shot from six yards was deflected behind in the 54th minute before Oshilaja headed wide from the resulting corner.

Wollacott had to be alert to come out and deny Macauley Bonne as the summer signing from Leyton Orient bore down on goal.

Moments later the Addicks were awarded a penalty when Sarr was fouled in the box by Liam Kitching.

However, Wollacott guessed the right way by diving to his left to save Jake Forster-Caskey's 68th minute spot-kick.

An excellent one-handed Ben Amos stop somehow denied Junior Mondal and the home keeper was relieved to see James Morton's 88th minute long range effort fly inches over.

Neither side could make the breakthrough and so it was penalties to decide who progressed to round two.

Forest Green led 3-2 on penalties after Joseph Mills, Dayle Grubb and Ebou Adams were on target for the hosts, with Bonne and Sarr doing likewise for the Addicks.

But Morgan's attempt hit the post for Charlton and although Oshilaja was successful from 12 yards, so were Morton and Shawn McCoulsky to seal a memorable victory for the visitors.