Sam Smith scored 11 goals for Reading in League One this season before joining Wrexham in January
Wrexham moved level on points with second-placed Wycombe Wanderers in League One as they claimed a hard-fought victory over Rotherham United at the Stok Racecourse.
Following an uneventful opening, Wrexham grew in attack as Seb Revan and Ryan Longman missed the target before Sam Smith threatened to break the deadlock.
Arthur Okonkwo had to be alert to deny Mallik Wilks before Dillon Phillips produced a stunning save to keep out Matty James' strike at the other end.
But striker Smith netted his first home goal for Wrexham on his 27th birthday after latching on to Jay Rodriguez's header to put the hosts ahead on 48 minutes.
Okonkwo brilliantly denied Pelly Ruddock Mpanzu as the Millers searched for an equaliser.
But the hosts - who had been without a home league win in four matches - kept a third successive league clean sheet to join the Chairboys' on 68 points after their late draw at Peterborough United.
Steve Evans' side stay 14th following a 15th league defeat of the campaign.
Wrexham boss Phil Parkinson said:
"Rotherham make it difficult for you, it's a first contacts and second balls game and you've got to be ready to deal with that, I thought we stuck to our task brilliantly on that side of it.
"Second half, Jay [Rodriguez] and Sam [Smith] have combined brilliantly and it's an important goal for us.
"I'm very pleased with the display. We've done the job well, defended long throws, corners and thoroughly deserved the win."
