|Totti contemplates another season without a scudetto in Rome [AFP]
Giampaolo Pazzini scored twice as Sampdoria stunned Roma 2-1 at the Stadio Olimpico to deal a potentially fatal blow to the club's title hopes after 24 games without a defeat.
Claudio Ranieri's side looked to heading back to the summit after Francesco Totti's 14th-minute goal but a second-half double from Pazzini sent Sampa up to fourth spot on Sunday.
Roma drop to second in the Italian Serie A, two points behind champions Inter Milan, who beat Atalanta 3-1 on Saturday.
Roma's first half performance was worthy of champions as time and again they carved Sampdoria open but the only surprise was that they managed just one meagre goal from their domination.
French winger Jeremy Menez brought a save out of Marco Storari before Brazilian centre-half Juan sent an overhead bicycle kick from a corner just wide.
After Storari had saved from Simone Perrotta, captain Francesco Totti gave Roma a 14th-minute lead.
Mirko Vucinic picked up the ball on the left and centred for Totti to glance a shot into the far corner.
And just five minutes later it was almost two as Vucinic released Totti in the inside left channel but his shot hit the near post.
Storari saved again from Menez while Totti and Vucinic were both off target as Roma kept the pressure on until half time.
But despite the one-way traffic of the first period, Sampdoria equalised soon after the restart as former Roma forward Antonio Cassano made space on the left and crossed to the back post where Pazzini's header found a gap between goalkeeper Julio Sergio's legs.
Roma were quickly back on the attack as Juan headed over from a corner but Sampdoria remained resolute.
Midway through the half coach Claudio Ranieri sent on striker Luca Toni as a last desperate throw of the dice.
Toni soon had an identical chance to Pazzini but this time Storari saved with his legs, before the on-loan Bayern Munich man had a strike ruled out for offside.
And nine minutes from time Storari tipped over a rocket from John-Arne Riise.
But four minutes later Roma were hit with a sucker punch as Sampdoria countered and Daniele Manini crossed for Pazzini to sidefoot home his second.
Juve Europe hopes
Earlier Juventus kept alive their hopes of Europa League football next season with a routine 3-0 win at home to Bari.
Vincenzo Iaquinta scored a brace in the second period, sandwiching an Alessandro Del Piero penalty.
They are sixth and six points clear of eigth-placed Genoa with three to play, meaning they are virtually assured of European football next season.
After a dire season, Juve coach Alberto Zaccheroni claimed his side had benefitted from having free midweeks to train properly, and for having their preferred forward combination.
"I've been saying the same things for months and I've been accused of making excuses but Diego is better when Iaquinta plays," he said.
"We've managed to find fluidity in training and I hope we continue in this way."
Livorno became the first club to be relegated this season despite a 3-1 win at home to Catania as Bologna's 2-1 home success against Parma left Livorno 10 points from safety with just three to play.
Siena are all but mathematically down after their 4-1 defeat at Udinese.