A superb scissor-kick from Radja Nainggolan helped secure the points as Roma closed the gap on Serie A leaders Juventus to just a point on Sunday after a 1-0 defeat of 10-man Genoa.
Gian Piero Gasperini's high-flyers welcomed Roma looking for their seventh win in 10 games but the visitors were given a huge incentive after Sampdoria held Juventus to a 1-1 draw in Turin.
Roma were given a boost on the half hour when goalkeeper Matti Perin was issued a straight red card for a challenge on Nainggolan in the area.
Although replacement Eugenio Lamanna did well to stop Adem Ljajic's resulting spot-kick on what was the 'keeper's Serie A debut, Roma's advantage would eventually tell.
Nainggolan found himself in space five minutes before half-time and produced a fine piece of mid-air wizardry to fire Maicon's delivery past a helpless Lamanna.
The result has given a huge boost to Rudi Garcia's men only days after their failure to reach the last 16 of the Champions League following a 2-0 home defeat to Manchester City.
"I'm happy we took the opportunity to cut the gap on Juventus to one point," Garcia told Sky Sport.
"We should have scored another goal after the break to ease the pressure. Playing here is tough, all teams will find it hard against Genoa at the Marassi."
Gasperini -- who was informed during half-time he would be sent to the stands for dissent -- insisted his side emerged with "even more belief" about their qualities.
"Playing three-quarters of the game a man down weighed heavily on us. It would have been an altogether different game otherwise," said Gasperini.
"But this has left me with even more belief about our qualities."
- Milan down Napoli -
In Sunday's late game goals by Jeremy Menez and Giacomo Bonaventura secured a precious 2-0 win for Milan over Napoli that moved Filippo Inzaghi's side up to sixth.
"We're delighted with the win, it's given us back our enthusiasm," Menez told Mediaset Premium.
"These three points will serve us well in the future. We've beaten a great Napoli side, we have to keep going like this."
Menez expertly skipped past French defender Kalidou Koulibaly in the sixth minute to send an angled strike past Rafael at the keeper's far post.
Milan 'keeper Diego Lopez kept the hosts in the game in the early stages with a series of saves from David Lopez and Jose Callejon, while defender Philippe Mexes almost turned the ball into his own net.
Milan kept up the pressure after the restart and were rewarded on 52 minutes when Bonaventura rose to meet Pablo Armero's inviting cross from the left to send a glancing header past Rafael.
Gonzalo Higuain and Duvan Zapata both saw late chances go amiss as Rafael Benitez's men succumbed to their first defeat since September to drop one place to seventh.
"The game started badly for us and we tried to react," Benitez told Sky Sport. "We had the chances but we just didn't put them away."
Earlier, Frenchman Patrice Evra gave champions Juve a 12th minute lead when he scored his first goal for the club with a header from a corner.
However Sampdoria, who handed Juventus their last home defeat, in January 2013, levelled six minutes when Italy striker Manolo Gabbiadini came off the bench to beat Gianluigi Buffon with a fine curling drive.
Juventus coach Massimiliano Allegri, who left Andrea Pirlo on the bench throughout, was left lamenting the series of chances the hosts spurned in a one-sided first half.
"We played well for 55 minutes, but in the opening half hour we just couldn't take the chances we created," said Allegri.
"The team did everything they could but we knew it was going to a difficult game. Unfortunately, we just didn't finish if off when we had the chance."
Gabbiadini finished off a nice Samp build-up by collecting Eder's pass on the right edge of the area and beating Buffon with a curling drive at the 'keeper's far post.
Lazio sit in third place, nine points adrift of Roma, following a 3-0 win over Atalanta on Saturday although Sampdoria, in fourth, and fifth-placed Genoa also have 26 points.
On Monday Empoli host Torino, while Inter travel to Chievo looking to move out of the bottom half of the table.
Source: AFP