A third penalty in two games saw Fleetwood Town dumped out of the Capital One cup.
Town took Championship Rotherham into extra time at the New York Stadium, a valiant rearguard action frustrating The Millers.
But a Matt Derbyshire penalty, 19 minutes into extra time finally ensured passage for Steve Evans’ men.
The home side could have sealed it in the 90 minutes had Paul Green’s blast, five minutes from time, not come back off the woodwork.
Had Matt Tidser’s reaction as the ball returned off the upright been quicker there might have been no need for a late night, despite a valiant rearguard effort from the League One visitors.
But he couldn’t get a vital touch to press home Rotherham’s dominance.
Chelseas loanee John Swift had twice tested Fleetwood keeper Chris Maxwell before the break as the Millers dominated posession and chances.
And after the break there were more good chances to take the advantage, Craig Morgan and Joe Skarz both bringing strong reaction saves from Fleetwood’s resolute stopper.
It took the visitors an hour to create an opening of their own, Gareth Evans coming closest for the Lancashire club, winning the race with Scott Loach, having been released by Jamie Proctor but unable to lift the ball over the Rotherham keeper.
It looked heading for penalties until Nathan Pond handled inside his own box, Derbyshire stepping up to slam the ball past Maxwell and end Fleetwood’s hopes.