Gary Speed's first game in management ended in defeat as Middlesbrough scraped to an unconvincing 1-0 win at the Riverside Stadium.
Kris Boyd grabbed the only goal of the game in the 52nd minute to earn a first league victory of the season for the Teessiders, managed by Speed's former Leeds team-mate Gordon Strachan.
Boyd's strike - his first for the club - was one of few memorable moments in a truly dismal encounter, which saw both sides display a disappointing lack of quality in the final third.
Scott McDonald's flick-on was misjudged by Blades skipper Chris Morgan and Boyd broke clear before slotting a low left-footed shot across Simonsen and into the corner.
United, who parted company with Kevin Blackwell following last weekend's 3-0 defeat to QPR, slip to the foot of the npower Championship on goals scored.
Yet they will consider themselves unfortunate not to have claimed a point against a Boro side desperately lacking in creativity and invention.
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