The last minute winner from former Miller Kevin Ellison came after the visitors had been reduced to 10 men when skipper Johnny Mullins was sent off with 19 minutes remaining for fouling Wright as he looked set to run on goal.
It proved a big decision as Rotherham had come from behind when Alex Revell deflected a Lionel Ainsworth shot past Barry Roche just after the hour.
Morecambe had started the second half in style when left back Robbie Threlfall scored his first goal for the club with a superb free kick.
He said: "We had plenty of chances in both halves to have won the game and we didn't do that.
"Jim Bentley is an honest guy and I think he would agree that we deserved to win the game but we didn't show the quality we needed where it mattered.
"There were times when we had men over but produced a sloppy final ball or chose the wrong option and that was disappointing.
"At the other end we made a couple of important mistakes and they proved costly but I just don't know how we didn't win the game.
"It's important that we put it to the back of our mind and move on to Exeter in midweek now and produce the type of response we all know we are capable of."
- Sports & Recreation
- Alex Revell
- Robbie Threlfall