Newcastle's Fabian Schar was knocked out cold after a clash with Arsenal's Eddie Nketiah.
The Magpies hosted the Gunners in a crucial clash at St James' Park, that remained goalless at half-time. Early in the second period a clearance was headed away by Schar, but not before Nketiah had challenged him in the air. The defender hit the deck and was knocked out.
His closest teammates quickly gestured for medical assistance as the Swiss defender laid motionless on the ground. Staff were quick to the scene and the defender was able to stand up within a couple of minutes. He was helped off the pitch as Jamaal Lascelles came on to replace him in what was a concussion substitution.
Nketiah was booked for the challenge, which was checked by the VAR and deemed not to be worthy of any further punishment.
Newcastle were aiming to spoil Arsenal's top four charge with the Gunners needing a win to get back into the Champions League places at the expense of rivals Tottenham. The Magpies have performed impressively since their January investment and are now eyeing a mid-table finish.
They took the lead just before the hour mark as Callum Wilson looked to beat Ben White to a cross at the near post and the ball diverted beyond Arsenal goalkeeper Aaron Ramsdale.
Eddie Howe said before the contest: "We’ve come a long way in a short period of time, I have to compliment the players, the staff, the togetherness has been incredible. A lot of wins which we needed from such a difficult position. "The one thing we haven’t achieved is a win over a top six team and a really complete performance.
"We don’t underestimate our task, a difficult game against a top team who have a good season despite being in slight transition they’re a very youthful team so we’re going to have to be strong today.You want to play with something on it and the pressure games will produce the best in the crowd and hopefully the best in us so hopefully they’re relishing that."
