A Louie Marsh header after the hour was all that separated the sides despite that dismissal as the Owlets worked hard in the face of a strong Blades outfit that included the likes of John Fleck, Ismaila Coulibaly and Ciaran Clark.
Tyreeq Bakinson and Jaden Brown were the first teamers on display for the boys in blue and white and many came out with credit.
Here are the ratings from a close run thing at S2.
1. A narrow defeat at Bramall Lane..
..but who stood out and who struggled? Here are our ratings from S2. Photo: UGC
2. Jack Hall - 7
Dealt with what came his way and his distribution was much improved on some recent outings. Looked a confident player and his handling was on-point, particularly from Coulibaly's firmly struck free-kick. Couldn't have done much for the goal. Photo: via swfc.co.uk
3. Mackenzie Maltby - 6
Dragged out to deal with the considerable threat of Buyabu several times, he battled hard. Got into a muddle to give the ball away to the dangerous Hackford midway through the first half but otherwise looked tidy. Photo: Joe Crann
4. Adam Alimi-Adetoro - 4
The man mountain centre-half was red-carded for a second yellow on 36 minutes when he lost grip of the breaking Hackford. Had won some important balls at that point but was a shade off the pace of an energetic Blades attack. Photo: Steve Ellis Steve Ellis