David De Gea made a huge goalkeeping howler as Manchester United suffered a 1-0 defeat at West Ham on Sunday that threatens to send their season into a tailspin.
Just a few days ago United were heavy favourites to finish in the Premier League's top four but now they are wobbling badly while the Hammers have edged closer to safety.
The result hinged on a catastrophic first-half error by De Gea, who let a tame shot from Said Benrahma squirm past him in the 27th minute after his team had largely dominated the opening period.
