
It finished 2-2 after the 90 minutes plus added time in south Wales, with Argyle rallying from a two-goal deficit in the second half to draw level through Bim Pepple and Tyreeq Bakinson, who equalised in the 90th minute.
That meant both teams picked up a point but then, under the competition rules, a penalty shoot-out was held with a bonus point at stake.
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Newport went first but Michael Adu-Poku had his spot kick saved by Argyle goalkeeper James Storer, who took over from Murphy Cooper as one of 10 changes to the team from the 2-0 League One win away to Leyton Orient on Saturday.
Harvey White slotted home next for the Pilgrims and they went on to win the shoot-out 5-4 after further penalties from Oli Irow, Xavier Amaechi, Pepple and Bradley Ibrahim.
Argyle are top of their group with five points, with Newport on four, followed by Crystal Palace under-21s on three and Swindon Town, who will play the Pilgrims at Home Park on November 10, yet to pick up a point.
Scroll below for all the updates from Chris Errington at Rodney Parade:
New UpdatesKey EventsAll squareView PostPepple scores for ArgyleView PostArgyle are behindView Post6th Oct21:05 BSTNewport 4 Argyle 5Bradley Ibrahim scores - and Argyle win the penalty shoot-out.