Goncalo Ramos gave Benfica the lead after 15 minutes as he headed the ball in from Joao Mario’s corner.
But the advantage didn’t last long as Miguel Almiron started and finished a fine attacking move to turn the ball in from Kieran Trippier’s cross.
Benfica restored their advantage as Alex Grimaldo curled a 25-yard free-kick into the top right corner of the goal.
But Trippier and Almiron combined again as the Paraguayan levelled the score at 2-2 going in at half-time.
Newcastle finished the match with 10 men after Joelinton was shown a second yellow card with nine minutes remaining.
Benfica made their man advantage count in the final minute of normal time as Henrique Araújo stroked home to make it 3-2.
Benfica restored their advantage as Alex Grimaldo curled a 25-yard free-kick into the top right corner of the goal.
5. Matt Targett - 5
Not the most comfortable evening for the Newcastle left-back as he struggled to get forward and couldn’t get his foot on the ball.
7. Bruno Guimaraes - 6
Played a neat ball through to release Almiron early on. Booked and may have been fortunate to stay on the pitch had it not been a friendly match. Photo: Owen Humphreys
8. Elliot Anderson - 6
Brought energy to the midfield and was able to put one teasing ball into the box. Photo: Getty