Newcastle are a point behind Tottenham in fifth place, with a game in hand. The only disappointment from an uplifting evening was the news that Miguel Almiron will miss the next six weeks after sustaining a thigh injury in training.
Eddie Howe, the Newcastle manager, said: “Confidence is key for any attacking player and Alexander’s penalty was ice-cool, it’s not easy to do that after the delay.
“He’s building up nicely towards having a huge impact for us. Both his goals were very well taken and he was a constant threat all night.
“Back-to-back wins are so difficult to achieve in the Premier League and this feels like a big moment in our season.”
Forest have built their survival hopes on the foundations of an impressive home record and this was their first defeat in ten league matches, stretching back to mid-September.
With their away form so poor since promotion, there is now added pressure on Cooper’s players to pick up points in front of their own supporters.
Many times this season they have ridden their luck at home, and they came so close here to another heroic result.
Evangelos Marinakis, the Forest owner, was understood to be “furious” with the performance of referee Paul Tierney, who did not punish a foul on Andre Ayew by Joe Willock seconds before Isak’s equaliser.
Steve Cooper, Forest’s head coach, said: “We were still going to be in a battle whatever happened here and we will do everything to stay above that relegation line.
“We’re all desperately disappointed but we’re all together and will keep fighting.
“We go into an international break now and that makes it doubly worse. Nothing can be solved tonight.”