League One leaders Rotherham stretched their unbeaten run to 15 games but were made to fight all the way as Covid-hit Oxford held them to a goalless draw at the Kassam Stadium.
Oxford, again missing 13 players, rode their luck in the first half when the Millers twice struck the woodwork.
But in the second half the U's created chances, only to be denied by keeper Viktor Johansson.
Rotherham were unfortunate not to go in front in the 11th minute when Michael Smith headed Mickel Miller's cross against the post.
Freddie Ladapo then headed Smith's cross against the bar just after the half hour.
Paul Warne's men saw another chance go begging when Smith headed Miller's cross over from a corner played short.
Herbie Kane produced Oxford's first effort on goal early in the second half with a 25-yard free-kick that Johansson clutched under his bar.
Oxford threatened again when Nathan Holland cut in from the left and hit a fierce drive that Johansson beat away, and the keeper also kept out efforts from Steve Seddon and Dan Agyei as the match finished all-square.