With Spurs leading 2-1, fans in the East Stand at St James' Park alerted players to the incident in the crowd.
Tottenham's Sergio Reguilon could be seen speaking to referee Andre Marriner, pointing to the stands.
His teammate Eric Dier sprinted across the pitch in an attempt to get a defibrillator taken over to the other side of the pitch by a physiotherapist.
After a brief delay, Marriner took both sets of players off the pitch while the person continued to get medical attention.
The Premier League said on Twitter that: "The match has been paused due to a medical issue in the crowd."
Newcastle provided an update to the fan's health after a short break with players ready to resume.
"The supporter who was in need of urgent medical assistance has been stabilized and is on their way to hospital," Newcastle said on Twitter. "Our thoughts are with them."
After a brief warm-up on the pitch, the first half resumed with seven minutes of additional time added, Newcastle wrote on Twitter.
Tottenham eventually won the game 3-2, with Tanguy Ndombele, Harry Kane and Son Heung-min scoring.