Denzel Hall's powerful volley proved to be the match-winner as Rotherham edged out Exeter.
Rotherham had early chances from crosses but Jordan Hugill and Kion Etete saw their headers kept out by diving saves from Joe Whitworth.
All the opportunities were falling to the home side and Hugill was denied again after bulldozing his way through and then Hall's shot was agonisingly wide.
Dutchman Hall would not be denied on 39 minutes though as he smashed in powerfully after a cross was cleared into his path by Ed Turns.
Rotherham's hopes of securing the points were thwarted in the second half by Whitworth as he kept out a header from debutant Thomas Holmes.
Joshua Kayode also had a couple of half chances with one whistling wide from Reece James's cross.
Exeter threatened a leveller late on but Sonny Cox could not get enough of a touch onto Josh Magennis' header to divert it in.
Magennis himself tapped home in added on time but was denied by an offside flag.
Report supplied by PA Media.
