Roma were denied a 12th successive Serie A victory by a last minute Internazionale equaliser at the Stadio Olimpico.
Rodrigo Taddei (pictured) had fired Roma ahead after great work from Brazilian Mancini down the left - which cut open the Inter defence.
Roma broke the Italian record for successive victories last week and looked on their way to another.
However, with almost their final attack of the game - Inter levelled as Marco Materazzi headed home from close-range.
Roma's failure to win also means Fiorentina have leap-frogged them into fourth place in Serie A.
Viola had an injury time winner to thank as they managed to secure a 2-1 win at home to Siena, although they looked to be cruising when Serie A top scorer Luca Toni grabbed his 23rd of the season with six minutes gone.
The visitors hit back through Simone Vergassola just nine minutes later, and it took until injury time for substitute Giampaolo Pazzini to claim the win for the Florentines.
Chievo moved one point closer to sixth-placed Livorno thanks to a 2-2 draw with Lazio.
The Biancocelesti edged in front when Stefano Mauri fired home on 31 minutes, and a Massimo Oddo penalty (67) earned then a draw after Chievo striker Simone Tiribocchi scored twice in three minutes before the break.
Livorno allowed Chievo to close as they lost 1-0 at home to Cagliari when David Suazo scored after 76 minutes.
Palermo's hopes of catching Sampdoria in ninth suffered a blow when they lost 2-0 at Lecce.
The victory pulled the home side off the bottom of the table, and to within six points of safety, as Mirko Vucinic (62) and Guillermo Giacomazzi (71) secured the three points.
Treviso were the fall-guys who replaced Lecce in 20th as a strike from Nicola Amoruso in the fifth minute of injury time gave Reggina a late, late win at Omobono Tenni.
Parma are now six points clear of the relegation zone after midfielder Mark Bresciano scored with just seven minutes to go to give them a 1-0 win at Messina.
Ascoli salvaged an unlikely 1-1 draw from their trip to Udinese, as the home side grabbed what looked like a winner on 77 minutes through Antonio Di Natale.
Ascoli's hopes seemed to have faded further when Roberto Guana was dismissed for two bookable offences, but with five minutes left on the clock Maurizio Domizzi scored from the penalty spot.
Click below for match summaries:
Chievo Verona 2-2 Lazio
Fiorentina 2-1 Siena
Lecce 2-0 Palermo
Livorno 0-1 Cagliari
Messina 0-1 Parma
Roma 1-1 Internazionale
Treviso 0-1 Reggina
Udinese 1-1 Ascoli