Sub Ben Williamson scored six minutes from the end of time as the Valiants ended their tour of the West County with a draw.
Vale welcomed Tom Pope, Richard Duffy and Chris Neal back into their starting line-up but were shocked on 11 minutes when Mudge put the home side ahead.
Vale were being frustrated by dogged defending and made five changes at half-time. Early into the second-half they should have equalised but Pope’s shot beat the keeper and hit both posts without going over the line.
However, Vale finally got their deserved goal when Williamson firmly headed a deep cross from eight yards out.
Port Vale: Chris Neal (Sam Johnson, 45), Adam Yates (Colin Daniel, 45), Carl Dickinson, Ryan McGivern (Chris Robertson, 45), Richard Duffy, Louis Dodds, Chris Lines (Chris Birchall, 45), Tom Pope, Michael Brown, Steve Jennings, Mark Marshall (Ben Williamson, 45).
Subs not used: Nathan Smith, Ryan Boot.