Louis Dodds scored his first of the season as the Valiants drew their first home game of the season.
Rob Page made two changes with Uche Ikpeazu and Ryan Inniss selected in place of AJ Leitch-Smith and Remie Streete. Gillingham included former Vale striker Ben Williamson.
Vale gifted the in-form Gills the lead on 17 minutes when keeper Alnwick picked up a back-pass and Bradley Dack scored from the resulting set-piece.
The Valiants felt that they had valid claims for a penalty when Andoh was brought down but a free-kick was awarded instead. However, Vale did equalise on 35 minutes when Louis Dodds scored after an excellent Vale move.
There was an early substitution as the impressive Andoh picked up an injury and was replaced by Kelly. Then the Valiants could have gone ahead early in the second period but Ryan Inniss hit the bar. Five minutes later, Ikpeazu blasted another Vale chance over the bar.
Rob Page brought on Brown and Daniel for Foley and Ikpeazu but to no avail as Gillingham held on and Vale were thwarted as they chased their first league win of the season.
Attendance: 5,067 (273 away supporters)