Napoli moved into third place in Serie A on Saturday after a 2-2 draw at Roma, but their hopes of making the Champions League next season were left on a knife-edge.
Napoli have 55 points, but will slip back to fourth on Sunday if Lazio avoid defeat against Udinese with three games left to play.
Napoli had to settle for a point when Brazilian Simplicio struck three minutes from time for Roma who remain seventh in the table, four points off the crucial third place.
Napoli thought they had the game won when Uruguayan striker Edinson Cavani struck a superb 67th-minute free-kick from 25 metres which beat Roma's Romanian goalkeeper Bogdan Lobont.
But they took a deserved lead in the 41st minute when Brazilian Marquinho hit the target from a cross by Aleandro Rosi.
Napoli levelled four minutes into the second period through Colombian star Juan Zuniga.
Despite Simplicio's late equaliser for Roma, the Olympic Stadium crowd jeered their team off the pitch as their Champions League hopes disappeared.
The draw kept Catania in eighth place, five points off their sixth-place target.
Source: AFP Global Edition