Matt Ritchie got Rafa Benitez’s side off to a flyer in their final outing of the calendar year, only for Nicolao Dumitru to restore parity before the break.
But, after a low-key period, United were given a new lease of life on the hour-mark, as the visitors’ Matt Mills was given his marching orders after two quick-fire bookings.
And, within minutes, the Magpies were in front once more, as Dwight Gayle rifled home from an acute angle.
Gayle took his tally for the season to 19 late on, bundling in from close range to put the outcome beyond doubt.
Exactly four weeks on from their controversial defeat at the City Ground, United came out of the traps quickly against Philippe Montanier’s side, and took the lead just four minutes in.
After Christian Atsu’s corner was only half-cleared, Paul Dummett was brought down by Forest’s Ben Osborn 25 yards out. Up stepped Ritchie, who got the better of ‘keeper Vladimir Stojkovic – albeit with the help of a wicked deflection.
Leading marksman Gayle twice went close for the Magpies in the following exchanges, nodding Isaac Hayden’s cross straight at Stojkovic, before seeing a low-struck effort blocked by Mills.
However, the visitors soon began to get a foothold in the game, and – 19 minutes in – Dumitru perhaps should have done better after finding a pocket of space on the edge of the area, lashing wide of the near post with time to pick his spot.
But, just shy of the half-hour mark, the Italian made no mistake when presented with another fine opportunity.
United failed to deal with Thomas Lam’s looping cross from the right, and – after cannoning off Eric Lichaj – the loose ball dropped invitingly for Dumitru, who duly slotted home.
Buoyed by their leveller, Forest ended the first half strongly, and – after a swift counter-attacking move – Nicklas Bendtner called Karl Darlow into action with a stinging drive from 18 yards.
After a scrappy start to the second period, Newcastle almost restored their lead on 58 minutes, as Ritchie met Atsu’s deflected cross deep inside the penalty area, only for Stojkovic to produce a fine stop.
But, just seconds later, Benitez’s side were given a timely boost. Forest skipper Mills was booked after bringing down Ayoze Perez just inside the visitors’ half, and – after throwing the ball at Gayle – the former Leicester City defender was shown another yellow card immediately.
United wasted little time in re-asserting their authority on proceedings.
Lichaj’s attempted clearance from a searching Ciaran Clark ball dropped kindly for Gayle six yards out, and – though the angle was tight – the frontman produced an emphatic finish.
Hayden then saw a powerful drive fly just wide from the edge of the area, before Gayle added his second in bizarre fashion.
Ritchie’s cross from the right bounced between two Forest defenders and onto the chest of the forward, and – somehow – the ball had enough on it to deceive Stojkovic and trickle over the line.
With the visitors dead and buried, there was little for Newcastle to worry about in the closing stages, Benitez’s men taking full advantage of Brighton & Hove Albion’s postponement to return to the top.
Newcastle United: Karl Darlow, DeAndre Yedlin, Ciaran Clark, Jamaal Lascelles, Paul Dummett, Jack Colback (Mohamed Diame 67), Isaac Hayden, Matt Ritchie (Achraf Lazaar 83), Ayoze Perez, Christian Atsu, Dwight Gayle (Aleksandar Mitrovic 88).
Nottingham Forest: Vladimir Stojkovic, Eric Lichaj, Matt Mills, Ben Osborn, Nicolao Dumitru (Britt Assombalonga 73), Nicklas Bendtner (David Vaughan 81), Hildeberto Pereira, Pajtim Kasami, Jack Hobbs, Thomas Lam (Anel Ahmedhodzic 84), Matty Cash.
Referee: Keith Stroud
Bookings: Newcastle United – Ciaran Clark (12), Jack Colback (53), DeAndre Yedlin (65); Nottingham Forest – Thomas Lam (26).
Sent off: Newcastle United – none; Nottingham Forest – Matt Mills (60).
