Huddersfield had the better of the play in the opening moments of the contest and could have been ahead but for a solid Scott Loach save from a testing Oliver Norwood free kick.
The hosts struggled to assert themselves and survived another scare when Joel Lynch headed over after finding space inside the box from a corner.
However, Paul Jewell's side nearly took the lead against the run of play when Lee Martin picked out Daryl Murphy, but the forward pulled his shot wide of the goal.
The visitors did find the goal that their impressive attacking deserved before the break when Adam Clayton fired a long-range strike past a helpless Loach.
Vaughan was close to extending his side's lead just 10 minutes into the second half but the on-loan Norwich striker's effort was tipped around the post by Loach.
Ipswich had improved after the interval and were rewarded in the 62nd minute when Murphy's cross found its way to Luke Chambers, who slotted home from inside the box.
Portman Road erupted with less than 20 minutes remaining when Chopra found space before applying a superb finish to give the hosts a crucial lead.
Huddersfield refused to give up in the final stages and grabbed an equaliser through Vaughan, with the striker tapping in a Danny Ward cross.
Simon Grayson's side had the opportunity to snatch victory late on when Jack Hunt was brought down inside the box but Loach pushed Vaughan's penalty against the bar to save a point for Ipswich.