New signing Rui Marques made his first appearance for Leeds following his arrival at Elland Road at the end of last month, playing the full 90 minutes at Kingston Park.
Leeds went behind on 35 minutes when Ian Bennett could only punch a shot out as far as Paul Huntington who clipped the ball back over his head.
Gylfi Einarsson equalised a few minutes before the break when he headed a Danny Pugh cross from the left past Newcastle keeper Smith.
Substitute Ian Morris then crossed for Michael Ricketts who hit a stunning bicycle kick giving the Whites the lead on 57 minutes.
Three minutes later Newcastle levelled when Carl Finnigan hit a low cross from inside the six-yard box.
A shot from Danny Pugh was deflected past the keeper after coming off Matthew Spring, but the goal was ruled out for off-side against Spring.
Then Bennett parried away a Brittain shot but could not prevent Peter Ramage putting away the loose ball to make it 3-2 for the Toon.
Morris then hit the crossbar but Leeds ended up with nothing on the night.
Newcastle: Smith, Gate (Farman 53), Elliott, Ramage, Huntington, Clark, Brittain, N'Zogbia, Finnigan (Smylie 63), Chopra (Walton 14), O'Brien.
Leeds: Bennett, Madden, Crainey, Marques, Walton (Parker 51), Einarsson, Richardson, Spring, Rothery (Morris 56), Ricketts (Bayly 63), Pugh.
Subs not used: Wilberforce, Gray.