In a first half where Costa Rica outplayed Italy, the Ticos took a deserved 1-0 victory before half-time with a beautifully taken header by Bryan Ruiz that hit the crossbar, bounced over the line and back out on to the field of play.
In real time, it was inconclusive whether the ball crossed the line or not. But due to the advantage of having goal line technology, the replay showed conclusive evidence that the whole of the ball had crossed the line.
A victory today for Costa Rica will knock England out of the World Cup.
Watch the replay of the goal here: