It looked a pretty straightforward offside call, but referee Kevin Stott expertly waved play on
Offside calls are one of the most contentious and difficult decisions a referee and his officials can make.
Games can be won and lost by a linesman's ability to accurately apply the offside rule. But with the introduction of goal-line technology and in-play replays in some parts of the world, big decisions are becoming more manageable to judge.
Still, with any official in charge of a match, there will always be room for human error.
Last night, Chicago Fire cruised to a 2-0 win over Real Salt Lake at Toyota Park with two goals coming in the opening 15 minutes of the game.
Arturo Alvarez wrapped up the win with the home side's second of the evening, but it was in the 11th minute when Chicago opened the scoring.
Nemanja Nikolic latched onto the end of a pass and off the back of the Real Salt Lake defenders, he streaked clear to apply a cool side-footed finish.
On first glance, Nikolic appeared to be a few yards offside. How referee Kevin Stott didn't spot this seemed a mystery to some of the travelling support.
Stott did however spot something else. The final touch did not come from a Chicago Fire player, instead it came from Real Salt Lake midfielder, Stephen Sunny.
With the final touch coming off Sunny, the offside rule was not applicable and Nikolic was well within his rights to streak clear and score.
The first replays still looked difficult to call, but only when the images when slowed right down and zoomed in on do we see the touch.