(CNN) -- Premier League leaders Chelsea suffered a humiliating 3-1 defeat to AS Roma who revived their Champions League qualifying hopes with the emphatic victory in the Stadio Olimpico on Tuesday night.
Panucci runs away in triumph after putting Roma ahead against Chelsea.
Roma went into the Group A game off the back of a 2-0 defeat at Juventus which left them one place above the Serie A relegation zone and with coach Luciano Spalletti under heavy pressure.
But their indifferent form counted for little as a first half strike from Christian Panucci and a superb double after the break from Mirko Vucinic sunk Luiz Felipe Scolari's men.
"First, we did not play very well," Scolari told Associated Press.
"Second, we made mistakes at critical times. (We gave) Roma their two best chances and Roma took it and killed the game.
"Roma maybe did not play one or two or three games very well here in Italy, but they have very good players and when you give them chances like tonight they're tough to stop."
Chelsea had made the better start as they looked for the win which would have all but sealed qualification for the knockout stages.
Roma goalkeeper Alexander Doni pulled off good saves from Deco and Frank Lampard before Panucci put the home side ahead in the 33rd minute.
He strode in unmarked to tap in a Cicinho cross from close range after the Chelsea defense fatally hesitated.
The second half was only three minutes old when Vucinic rifled home a shot from outside the penalty area which left Petr Cech clutching at fresh air.
Chelsea pushed forward, but were caught out again in the 58th minute as Jon Obi Mikel was robbed by Vucinic who stole forward to beat Cech with a low shot. It was his eighth goal in 18 Champions League appearances.
Chelsea pulled one back on 75 minutes as Deco's shot was only parried out to captain John Terry, who tapped in from close range with Roma appealing for handball.
But they never looked capable of getting back on even terms as Roma held on for a famous victory, made easier by the sending off on 80 minutes of Deco, who was sent off for a second yellow card.
With Bordeaux winning 2-1 at Romanian minnows CFR Cluj, the situation in the group remains tight.
Chelsea still lead on seven points from four games, closely trailed by Roma and Bordeaux on six points and Cluj on four.