The Blades had earler led before going 2-1 and 3-2 behind before John Egan's 94th-minute equaliser forced a replay at Bramall Lane.
United’s Daniel Jebbison was sent off as the Blades finished with 10 men, and here’s how we rated the United side in Wales...
1. Wrexham, Wales, 29th January 2023. Daniel Jebbison of Sheffield Utd is sent off during the The FA Cup match at the Racecourse Stadium, Wrexham. Picture credit should read: Gary Oakley / Sportimage
Daniel Jebbison of Sheffield United is sent off at Wrexham: Gary Oakley / Sportimage Photo: Gary Oakley
2. Adam Davies 5
May have had his heart in his mouth when Mullin went down under his challenge after racing through but the ref waved away the penalty appeals. Spilled one of Tozer's long throws soon after but the follow-up was blazed over the bar. On first glance may have done better with a shot in the lead up to Wrexham's equaliser RESTRICTIONS: EDITORIAL USE ONLY No use with unauthorised audio, video, data, fixture lists, club/league logos or "live" services. Online in-match use limited to 120 images, no video emulation. No use in betting, games or single club/league/player publications. Photo: Peter Byrne
3. Jayden Bogle 5
Took a whack to the face accidentally as he looked to race away with the ball and had claret pouring from his nose. Beaten by Mullin out on the left before he tested Davies' handling with a well-struck effort but offered a threat going forward too Photo: Michael Steele
4. Anel Ahmedhodzic 5
Didn't look at his most composed against Wrexham's multiple threats but had some decent moments too, in attack and defence Photo: Gary Oakley