Paul Mullin's goal 16 seconds into his return to the starting lineup was enough to see Wrexham beat Rotherham at the AESSEAL New York Stadium.
Mullin replaced injured Jack Marriott to make only his second league start of the campaign following back surgery in the summer.
He volleyed home Ryan Bennett's cross for his first league goal of the season to clinch just a second away win in League One.
The win was tempered by confirmation that Marriott suffered a fractured leg in training and will undergo surgery on Monday.
Here, Wrexham had to defend well in the second half to keep out an in-form Rotherham side who had lost just one of their previous nine games.
But, like Wrexham, they were also without their top scorer in Jonson Clarke-Harris and drew a blank.
Joe Rafferty volleyed wide and then set up captain Hakeem Odoffin whose effort was comfortably saved by Arthur Okonkwo.
But Wrexham's goalkeeper was at full stretch to keep out Joe Powell's deflected free-kick.
Mullin was shown a yellow card for a late challenge on Millers goalkeeper Cameron Dawson on the stroke of half-time.
The pair also shared plenty of exchanges after the break when Dawson twice denied the Dragons' striker, either sides of saves from Tom O'Connor's free kick and Dan Scarr's effort.
Rotherham also had chances, but Sam Nombe should have done better after Wrexham failed to clear a corner before Cohen Bramall's free-kick went close.
Wrexham manager Phil Parkinson said: "It's a great result for us at a tough place to come.
"Getting the early goal was terrific for us and I'm delighted for [Mullin] who produced a brilliant finish as he has done time and again for us.
"But it was also the all-round discipline, fighting spirit and quality when we needed it was great today. We were against a team who were in the Championship last season but it was a controlled performance both with and without the ball."