(Reuters) -Lorenzo Pellegrini and Romelu Lukaku scored to give AS Roma a 2-0 home win over Napoli in Serie A on Saturday as Matteo Politano and Victor Osimhen were sent off for the visitors.

Roma moved up to sixth place on 28 points, one ahead of Napoli who dropped to seventh. Walter Mazzarri has now lost five games from eight in all competitions since taking over from Rudi Garcia in November.

The opening goal of a nervy game came in the 76th minute when Pellegrini, only on the pitch five minutes, hit a half-volley on the turn into the top corner when the ball fell to him after a mis-hit shot from Stephan El Shaarawy.

Champions Napoli were already down to 10 men after Politano was sent off in the 66th minute for kicking out at Nicola Zalewski when the Roma player pulled him back by his jersey.

Osimhen picked up a second yellow card in the 86th minute, and Napoli had goalkeeper Alex Meret to thank for keeping the score at 1-0 before Lukaku wrapped up the win in the 96th minute with Napoli chasing a late equaliser.

From a counter-attack, Lukaku picked up possession inside the Napoli half and passed the ball to Ndicka who played it back for the Belgian striker to fire his shot into the net.

In the first half, the referee reached for the yellow card on six occasions, including booking both managers, as Napoli dominated possession, and it was Roma who looked the more dangerous side.

"Maybe you don't agree, but my feeling is that right after 5-10 minutes we would have won the game," Roma manager Jose Mourinho told DAZN.

"Roma came in very, very well, we were always in control against a much stronger team from a technical point of view."

The first chance fell to Roma when Lukaku laid a pass back to Edoardo Bove and his shot from the edge of the area clipped the crossbar.

The game was still a cagey affair until Politano's moment of madness. Mourinho made a triple-change, and it was Pellegrini who made the biggest impact with his first touch of the ball.

"Then with 10 men we had an advantage, we took advantage of it well with the changes and with our interpretation. I think it's a well-deserved victory," Mourinho said.

Napoli pushed for an equaliser but created no real chances, and Meret was quick off his line to palm away a Lukaku effort before Osimhen's red card ended Napoli's hopes.

Bologna moved back up to fourth spot as a late goal from Lewis Ferguson gave them a 1-0 win over Atalanta.

(Reporting by Trevor Stynes, editing by Ed Osmond)