The final score may seem as though United had a fairly easy ride in London but it was the hosts who came out of the stumbling blocks first; Bidwell tested the Blades defence - forcing Williams to concede an early corner. They continued to press in the United half and defended well; Hill twice beating a tall Donaldson to headers.
Only six minutes had passed on the clock when the Bees were punished for good early possession, Welsh striker Evans capitalised on a Porter flick-on to fire the ball home with much delight to the traveling fans.
The team had traveled down south a day prior to the game and were at that time second in the table and just one point ahead of there nearest opposition (Sheffield Wednesday) and was looking to turn around a bad form which had seen them win just once in four matches.
Brentford, who required maximum points just as much as there opposition were quick on the break and threatened in patches - on 22 minutes captain Michael Doyle thwarted such an attack before Evans was caught napping and missed an opportunity to double his daily tally.
With six minutes remaining of the half the Welsh forward was handed another chance to double the lead after charging through a gap between the centre-halves but with the goal gaping he unusually fired wide! Porter was denied when Moore clawed out the former Derby County strikers header to take the break at 1-0.
It was Danny Wilson's Blades who got themselves a good start in the second half and again after six minutes saw the net bulging through a Evans strike. Moments earlier he had flashed wide following a well worked free-kick but was to make no mistake when Moore's free-kick landed straight to him, allowing him to round the keeper and slot home.
The hosts still forged good attacks and undoubtedly will be feeling that they should have taking something away from the match; creating 14 attempts at goal - double than United's efforts.
With moments to spare of the afternoon Moore denied Evans of a first Blades hat-trick with his legs as United came away with three valuable points. Wednesday had already claimed there victory after storming into a 3-0 lead against Bournemouth inside ten minutes, whilst a Jonathan Forte hat-trick was enough to secure an unlikely 4-2 win for Nott's County at Charlton Athletic.