The Blades had to come from behind to take all three points, after going behind early on, while they withstood a late Cardiff onslaught after they pulled one back with a few minutes remaining.
Victory means Paul Heckingbottom has taken six points from his two games in permanent charge. Here’s how our man Danny Hall rated United’s players…
1. Wes Foderingham 8
Made a superb save from Nelson after his header from a corner took a deflection, and maybe two, before Foderingham managed to keep it out. Did well to deny Davies soon after City's opening goal and made a smart save to keep out Kieffer Moore's header late on too Photo: Simon Bellis
2. Jayden Bogle 7
Brilliant cross early in the game found Sharp in the middle, but the Blades skipper couldn't convert. Did excellently to set up Sharp's goal with Gibbs-White and could have had a goal himself from a deep cross, but he couldn't direct the ball goalwards at the back post Photo: Ashley Crowden
3. Chris Basham 7
Didn't put a foot wrong all afternoon and on a few occasions was on hand to snuff out the danger as City looked to get the better of his teammates Photo: Simon Bellis
4. John Egan 6
Will have probably breathed a sigh of relief when he saw the teamsheet and noticed that Kieffer Moore was on the bench. United look more solid overall after switching back to a back three, but still have a habit of conceding goals from set-pieces Photo: Simon Bellis