Napoli allowed an 88th-minute equalizer in a 2-2 draw at Roma in the Serie A on Saturday, which could be a big blow in its attempt at returning to the Champions League.
Napoli moved level with Lazio for third place, which carries a spot in Champions League qualifying, but Lazio holds the tiebreaker and has a chance to move back ahead at Udinese on Sunday.
Napoli looked to be heading for their third straight win after Edinson Cavani put them in front for the first time in the 67th minute.
Marquinho had given Roma a 41st-minute lead before Juan Zuniga equalised for the visitors early in the second half.
Simplicio, on as a substitute, then came to Roma's rescue and hit the back of the net three minutes from time.
The top three teams in Italy's top flight qualify for the Champions League next season.
Roma, meanwhile, remained in seventh place.
The hosts went into the game looking to bounce back from consecutive defeats to Juventus and Fiorentina and had the first chance in the seventh minute when Marquinho's header from Francesco Totti's cross was kept out by Napoli goalkeeper Morgan De Sanctis.
Napoli could have taken the lead three minutes later when Blerim Dzjemaili fed Cavani in the box but he struck the ball wide of the far post.
Cavani then acted as provider and found Marek Hamsik in the area. However his attempt from 12 yards was saved by Roma goalkeeper Bodgan Lobont.
Instead it was the hosts who went in front before the interval.
Aleandro Rossi's cross from the right found Marquinho in the heart of the area and his left-footed strike beat De Sanctis.
Napoli played with a greater sense of urgency after the restart and drew level in the 48th minute.
Zuniga found space outside the area and struck the ball towards the far post and out of Lobont's reach.
The visitors continued to put pressure on Roma's defence and on the hour mark, Lobont kept out Gokhan Inler and Cavani's goalbound attempts.
Napoli's efforts paid off as Cavani's right-footed shot from 30 yards beat Lobont.
Yet it was Roma who had the last say.
Simplicio got behind substitute Junior Tallo's cross and struck the ball from the heart of the area past De Sanctis and into the bottom right corner of the goal.
