Chelsea were given a real scare at home against Southampton on Saturday afternoon.
The Blues took the lead after just nine minutes through Trevoh Chalobah.
But Thomas Tuchel's side were pegged back in the second half.
Ben Chilwell gave away a penalty and James Ward-Prowse made no mistake from the spot.
It looked like Chelsea would drop points as they struggled to re-establish their lead.
But the turning point came when Ward-Prowse was sent off in the 77th minute for a late foul on Jorginho.
The English midfielder was originally given a yellow card but referee Martin Atkinson gave him his marching orders after consultation with the pitch-side monitor.
Chelsea would go on to make their advantage count as they ran out 3-1 victors.
Timo Werner netted in the 84th minute, before Chilwell netted one of the craziest goals of 2021 with one minute of normal time remaining.
Romelu Lukaku and Cesar Azpilicueta both hit the post from close range before Chilwell produced a stunning volley from a tight angle.
It looked as if Alex McCarthy had kept Chilwell's effort out but technology ruled that the ball had just crossed the line.
What an absolutely mad sequence.
View some reaction to the goal below...
It was a brilliant effort from McCarthy to try and keep his countryman's effort out.
You've got to say, though, Chilwell's technique for that volley deserved a goal.
Manchester United 1-1 Everton Reaction Show | The Football Terrace
Chelsea's victory means they have gone back to the summit of the Premier League having obtained 16 points from a possible 21.
They could drop out of top spot by the end of the weekend, though, depending on the result of Liverpool vs Manchester City on Sunday evening.