MILAN (AFP) - Roberto Mancini hit out at a refereeing "mistake" that dented Inter Milan's title hopes after a last-gasp 1-0 defeat by Sassuolo at the San Siro on Sunday.

Inter spurned a host of chances in a lively encounter and paid for those misses at the death when Domenico Berardi beat Samir Handanovic from the spot after falling under a challenge from Brazilian defender Joao Miranda.

Inter remain top with a one-point lead over Fiorentina and Napoli, although the latter will reclaim the Serie A lead with a win away to Frosinone on Sunday.

Mancini admitted his side's lack of clinical finishing was a factor, but the Italian who led Inter to three consecutive league titles in his previous spell in charge in 2004-2008 hit out at the referee's decision to award a last-gasp penalty.

"Maybe we lacked some lucidity when it came to putting our chances away, but the penalty that came at the end was a terrible mistake. That's football though," he told Sky Sport.

"Now, we have to roll up our sleeves and get back to work. We had two or three clear chances, and they had only one with Simone Missiroli."

Sassuolo coach Eusebio di Francesco hailed Miranda as a "top defender", but the visiting coach was adamant the Brazilian was at fault for his side's penalty.

"I don't think it's right to reduce the outcome of this game to one episode and I don't want to talk too much about refereeing decisions," he told Sky Sport.

"But I can say that it was a clear and indisputable penalty."

Inter's second successive home defeat, after a 2-1 reverse by Lazio prior to the festive break, came days after Mancini said he did not mind his side's penchant for winning games 1-0.

Inter had ample opportunity to change the outcome with an early goal, but were wasteful throughout and especially during a promising start.

Mauro Icardi flashed a shot wide after being sent through by Gary Medel's floated cross and moments later Adem Ljajic missed a great chance, firing inches wide after running across the six-yard box.

Inter 'keeper Samir Handanovic went on to produce a series of fine saves, keeping out Nicola Sansone's free kick with one hand before blocking Missiroli's close-range effort with his chest and then producing another one-handed save to push Berardi's dipping free kick to safety.

Inter should have taken a 43rd-minute lead, when an exchange of passes between Icardi and Ljajic saw the latter hit a curling effort that Andrea Consigli finger-tipped out for a corner.

Both sides spurned chances in the second half, substitute Rodrigo Palacio's close-range effort from Icardi's cutback notably blocked yards from goal by Federico Peluso.

Di Francesco replaced Sansone with Antonio Floro Flores and moments later the striker's acrobatic bicycle kick from Berardi's free kick was somehow blocked by an alert Handanovic.

On a Sassuolo offensive, Miranda was unlucky to clatter into Berardi in the area but the referee pointed to the spot and the striker made no mistake.

"We knew we were up against the league leaders, but we played as a team and we deserved the win," said Berardi.

Despite Sassuolo moving back up into sixth spot, he played down the Tuscans' Europa League qualification hopes.

"Our priority is survival, then we'll see what happens."