Nine-man Newcastle United were beaten 2-1 by Nottingham Forest on a dramatic night at the City Ground.
Referee Stephen Martin controversially sent off Jonjo Shelvey and Paul Dummett and awarded penalties against the pair.
Former Forest goalkeeper Karl Darlow saved both spot kicks.
Shelvey will now be banned up to his Football Association misconduct hearing later this month.
Matt Ritchie gave Newcastle a 45th-minute lead with a fine goal.
But second-half strikes from Nicklas Bendtner and Matty Cash saw Champioinship leaders United suffer a third successive defeat in all competitions.
But the scoreline doesn't tell the whole story.
The first half came to life in the 33rd minute when Shelvey and Henri Lansbury, both prone on the turf, clashed.
Shelvey appeared to aim a kick at Lansbury, which was missed by the referee. However, Martin's assistant flagged and Martin sent off Shelvey and pointed to the spot.
Darlow stopped Bendtner's penalty to the delight of the club's 1,866 travelling fans.
Ritchie put Newcastle ahead in the 45th minute, but more was to come before the interval.
Lansbury, under a challenge from Dummett, went down in the box and Martin again pointed to the spot – and sent off Dummett.
More remarkably, Darlow stopped the penalty, this time taken by Lansbury himself.
Benitez – who had made four changes to the side knocked out of the EFL Cup on Tuesday night – replaced Ayoze Perez with Vurnon Anita for the second half.
But their resistance was broken in the 52nd minute, when Bendtner forced the ball over the line after a goalmouth scramble.
And a late own goal from Jamaal Lascelles saw Forest claim all three points.
NOTTINGHAM FOREST: Stojkovic, Cash, Mancienne (Assombalonga, 46), Mills, Perquis, Lichaj, Lam (Carayol, 65), Kasami, Lansbury, Osborn, Bendtner (Vellios, 78). Subs not used: Henderson, Vaughan, Hobbs, Grant.
NEWCASTLE UNITED: Darlow; Yedlin, Lascelles, Clark, Dummett; Shelvey, Hayden; Ritchie, Perez (Anita, 46), Gouffran (Diame, 76); Gayle (Mitrovic, 87). Subs not used: Sels, Mbemba, Tiote, Atsu.
Goals: Ritchie 45, Bendtner 52, Lascelles 86 (og)
Bookings: Mancienne 44, Darlow 45
Sent off: Shelvey 33, Dummett 45
Referee: Stephen Martin (Staffordshire)
Attendance: 21,317 (1,866 Newcastle)