Middlesbrough have spent millions on attacking talent this summer, but it was one of the survivors from Premier League relegation who earned their first win in the Championship this season.
Rudy Gestede took advantage of poor Sheffield United defending following a lobbed Patrick Bamford through ball, and looped a header over former Boro goalkeeper Jamal Blackman.
Newly promoted United were competitive, with Darren Randolph having to make a fine diving save to deny Paul Coutts after the break and Chris Basham having a stoppage time header ruled out for a marginal offside, but Boro held on for three points.