Newcastle United toasted a new hero after a magnificent match-winning home debut from Moussa Sissoko, while Chelsea could soon be looking for yet another manager as the pressure grows on Rafael Benitez.
The London club, who have now won one game in six, were poor in the first half, much better at the start of the second, yet still managed to lose a game they had fought back to lead, thanks to sumptuous strikes from Frank Lampard and Juan Mata. Sissoko inspired the comeback that had
St James' Park enthralled.
Just as Chelsea did at Reading in their last game, Benitez's side have thrown away three points from a winning position.
The Spaniard, an unpopular replacement for Roberto Di Matteo, is now fighting just to remain as interim manager until the end of the season.
Even when they play well, as Chelsea did for 30 minutes after half-time, they are still failing to control games in the manner expected of such an experienced and expensively assembled squad.
When Mata scored their second goal, curling the ball into the top corner after Lampard had found the net with a thunderous long-range strike, Chelsea's fans chose to remind their hosts that they are the champions of Europe.
But that title was earned last year and the way they surrendered that lead was very much indicative their current status.
If they are not careful, the memory of that famous victory in Munich will provide scant comfort should Chelsea miss out on a top-four finish in May.
"We are still aiming for the top three or four," said Benitez when asked about the growing pressure on him. "The reaction of the players in the second half was fantastic and that was really pleasing.
"What we have to improve is how we manage situations like this. We allowed them to play on the counter-attack when we were leading the game."
It has been a season full of suffering on Tyneside, but Newcastle appear to have found the perfect painkiller in the January transfer window. Sissoko was the star performer, although Mathieu Debuchy at right-back and Yoan Gouffran - another January acquisition - on the right side of midfield were almost as impressive.
The plan had been to sign Sissoko on a free transfer at the end of the season, but Newcastle, wary of their precarious league position, instead persuaded Toulouse to release him early for a little more than pounds 2?million.
"I don't think I've seen a better home debut," Pardew said. "I've seen two players since I've been here who I've been desperate to sign. One is Yohan Cabaye, one is Moussa.
"What a magnificent player he is and he has already brought us a power and a presence we have lacked. He's going to be a massive signing for us. This was a fabulous game and a brilliant result."
Jonas Gutierrez had given Newcastle the deserved lead in the first half when he beat John Terry to Davide Santon's cross.
By then Papiss Cisse had already missed a wonderful chance when he shot weakly, allowing Petr Cech to save, while Sissoko had fired over the bar after a sweeping counter-attack.
Chelsea had also missed chances. Lampard blazed wildly over the bar from Ashley Cole's pull back, before Demba Ba had two chances to beat Tim Krul, shooting straight at the Dutch goalkeeper before heading the rebound wide.
The Senegal striker suffered a painful return to St James' Park. Caught full in the face by Fabricio Coloccini while going for
that header, Ba's nose was smashed and forced him off before half-time.
That gave Benitez a chance to divert attention from the defeat, but his was not an entirely convincing argument. "It was a penalty and a red card," he said. "If that happened in the middle of the park, play would have been brought back, a free-kick given and a red card shown.
"It should not be different just because it's in the area. He has kicked him in the face, broken his nose and he is bleeding all over the place."
By the same logic, it could be argued that Ramires should have been sent off for a two-footed lunge on Gutierrez. Contentious refereeing decisions cannot disguise the fact that Newcastle, over the 90 minutes, deserved to win and to move further away from relegation trouble.
Sissoko scored his first goal when he tapped in a rebound after Gouffran's effort had been well saved. Sissoko was then denied a second by Cech's fingertips after the midfielder had sprinted past Cole.
However, the Chelsea goalkeeper could not keep out Sissoko's low shot in the 90th minute after Santon had picked him out running in from the edge of the area.