With 20 minutes gone, Gary Cahill picked out Victor Moses out on the right with a terrific diagonal ball.
The Nigerian international took the ball down on his chest and crossed into the middle.
Burnley appeared to have the situation under control, with four players between the crosser and the nearest Chelsea defender, however that wasn't the case.
Pope attempted to intercept the ball in but could only palm it against Long, who could do nothing but watch on as the ball dropped into the back of his own net.
Check out the strike for yourself below:
April 19, 2018