Florian Lejeune was stretchered off as Newcastle United's five-game winning run at St James's Park was brought to an end.
A second-half penalty from Luka Milivojevic gave Crystal Palace a 1-0 win this afternoon.
A distraught Lejeune had been carried off the field earlier in the half after going down following a challenge on Andros Townsend.
Newcastle were left to rue a series of first-half chances – and the DeAndre Yedlin challenge on Wilfried Zaha which led to the penalty.
United remain 14th in the Premier League and seven points above the relegation zone.
Rafa Benitez had made two changes, recalling Fabian Schar and Ki Sung-yueng to his starting XI in place of Paul Dummett and the injured Mohamed Diame. Jonjo Shelvey, again, was named on the bench.
Newcastle took the game to Palace in the first half, and Rondon had a goal disallowed for offside after bundling the ball over the line following a Matt Ritchie flick-on.
Rondon should have done better with the 30th-minute header he put over from a DeAndre Yedlin cross. The striker had another effort stopped on the line by Vicente Guaita, who had an uncomfortable half.
Miguel Almiron had a shot deflected over before Palace had the ball in the net at the other end of the pitch. James Tomkins netted from a Milivojevic corner, but James McArthur was stood in front of Martin Dubravka in an offside position and raised his flag.
Lejeune went down after challenging Andros Townsend on the hour mark.
The defender – who ruptured his anterior cruciate ligament last summer – was stretchered off with a strapped left leg after lengthy treatment. Dummett replaced him.
Newcastle had been unable to maintain their first-half momentum, though Yedlin wasn't far away with one shot from distance.
Benitez sent on Shelvey for the last 14 minutes, but he wasn't able to force a breakthrough for United.
Yedlin clipped Zaha in the box with nine minutes left on the clock, and Milivojevic, the visitors' captain, stepped up to take the resulting penalty, which was their first shot on target.
There were seven minutes of added time to play following the stoppage for Lejeune's injury, but was no way back for Newcastle.
NEWCASTLE UNITED: Dubravka; Yedlin, Schar, Lascelles, Lejeune (Dummett, 65), Ritchie (Atsu, 90); Perez, Hayden, Ki (Shelvey, 76), Almiron; Rondon. Subs: Darlow, Manquillo, Fernandez, Muto.
CRYSTAL PALACE: Guaita; Wan-Bissaka, Kelly, Tomkins (Dann, 73), Van Aanholt; McArthur, Milivojevic, Schlupp; Townsend (Kouyate, 85), Batshuayi (Benteke, 65), Zaha. Subs: Hennessey, Ward, Ayew, Woods.
Goal: Milivojevic 81 (pen)
Bookings: Kelly 45, Hayden 79
Referee: Stuart Attwell (Warwickshire)