Roma fell to their first defeat in Serie A since Nov. 1 to see their grasp on a place in the Champions League next season loosen with a 2-0 loss at home to Sampdoria.
Lorenzo De Silvestri and Luis Muriel grabbed the goals for the Blucerchiati, who weathered a first-half storm before striking efficiently in the second half to boost their own hopes of qualifying for Europe next season.
Roma's sorry evening ended on an even worse note with Seydou Keita shown a red card late on as the Giallorossi also helped Juventus get one hand on a fourth straight Serie A title, thanks to their 14-point advantage with 11 games remaining.
Before making headlines for the wrong reasons, Keita could have stolen them for all the right reasons with a textbook volley in the 18th minute which would have been a contender for goal of the month, had the linesman's flag not been raised.
Francesco Totti tested Emiliano Viviano at his near post on what was going to be a busy night for the Sampdoria number one.
He also denied Gervinho and Totti again before, on the stroke of halftime, saving the blushes of Vasco Regini when he diverted Gervinho's cross towards his own goal, but saw his goalkeeper stop the ball right on the line.
Gervinho tested Viviano again going into stoppage time, but the Samp custodian replied with another fine stop to keep his team on terms.
Having survived, thanks largely to their goalkeeper, Samp then took the lead with one of their first attacks of the game.
On the hour mark, Samuel Eto'o pulled the ball back to the edge of the six-yard box where De Silvestri had all the time in the world to turn it in.
Vasilis Torosidis sent a shot over in reaction to falling behind, but as Roma committed more and more players forward, Muriel punished them.
The former Udinese forward raced almost 50 yards with the ball at his feet before curling his shot against the right-hand post.
It fell out for Alfred Duncan, who in turn teed up Eder, and although he lost a shooting opportunity, the ball fell back for Muriel who swept it in at the second attempt.
Roma were urged on by their coach Rudi Garcia, but as they prepared for a corner, Keita argued with the referee to earn a yellow card. Ironic applause saw him shown a second yellow to compound Roma's woes on a night which also saw city rivals Lazio close to within a point.