As the two sides prepared to do battle in the second leg of their Europa League semi-final, the woman was addressing the camera when a ball looped up in the air.
A man – who appears to be from the Valencia coaching staff – moves into shot as he looks to stop the ball but cannot get there in time.
The woman is then hit in the back of the head and falls over in full view of the camera.
It is not yet known exactly who she is or what TV station she works for but BT Sport presenter Jake Humphrey revealed he was close to the incident.
Humphrey posted the video on his official Twitter account and joked they were aiming for his colleague Martin Keown.
“This happened about 5 yards from us,” he said.
“I think they were aiming for Keown.”
Arsenal had earlier fallen behind to Kevin Gameiro’s strike after just 11 minutes.
The Frenchman had a glorious chance to double their lead on the night and put the hosts ahead on away goals overall.
However, he failed to react to a shot from Goncalo Guedes and the Gunners allowed to clear.
Arsenal punished them just six minutes later when Pierre-Emerick Aubameyang latched onto Alexandre Lacazette’s header.
Aubameyang pulled the trigger from the edge of the area and expertly found the bottom corner to cancel out Valencia’s away goal from the first leg.
The goal appeared to calm their nerves and Lacazette might have put them 2-1 ahead from Aubameyang’s centre.
However, he could only find the outside of the post when he looked certain to score and the sides went in level at the break.
Lacazette made amends shortly after half-time with a sublime finish in the 50t minute to put them on course for the final.
However, they were given another late scare when Gameiro scrambled one in to make it 2-2 but Aubameyang made it 3-2 shortly after.