Erik ten Hag called on Manchester United to become faultless as they took back control of their Champions League aspirations.
Marcus Rashford's winner was enough to beat Brentford, United's first Premier League victory since February 19 and a reaction to the dismal defeat at Newcastle United on Sunday.
But Thomas Frank was left rueing substitute Kevin Schade's huge missed chance - fashioned after the on-loan striker nipped in front of Raphael Varane - and Ten Hag is wary of lapsed defensive concentration. The Dutchman added that United still have a margin for improvement.