The Spaniard made his third error leading to a goal in four games on Sunday afternoon, costing United their well-earned lead against the Blues.
As half-time loomed, Antonio Rudiger unleashed a powerful effort from 35 yards, which sailed towards De Gea.
But the United No1 spilled the shot into the path of the onrushing Marcos Alonso, who sprung onto the ball and dinked home from an acute angle.
De Gea stood in disbelief at the exacerbation of his poor run of form, shaking his bowed head.
As the half-time whistle blew, De Gea lightly trotted towards the tunnel, located at the other end of the ground.
Tempers have been bubbling over De Gea’s form and reluctance to sign a new contract, but the Stretford End was supportive of their beloved keeper.
“David de Gea… David de Gea… David de Gea…” they chanted in a classy show of support.
The keeper raised his hand to the acknowledge the fans’ support, still embarrassed by the howler which cost his team.
David de Gea made a howler to gift Chelsea their equaliser (Image: Sky Sports)
Gary Neville was commentating on the crunch match, which could well determine the top four positions come the end of the season, and felt sympathy for the 28-year-old.
The Sky Sports pundit opined: ”David de Gea, I don’t know what to say. He is having a nightmare of a time.
“Well done to Alonso, who is alive and alert. But De Gea, what a time he is having.
“I remember I had a nightmare time at the end of the 1999/2000 season and I just needed the summer.