Both sides have struggled for any sort of form in the closing weeks of the campaign, though, meaning that there is little to choose between the two in what is a straight shootout for a place in the top three.
Having announced his intention to step down as manager at the end of the season, when he will almost certainly walk straight into the vacant Real Madrid job, Rafael Benitez now has the chance to part company with Napoli on a high.
It could have been even better, of course, had they not come out second best in their Europa League semi-final clash against Dnipro Dnipropetrovsk earlier this month. All the talk in the build-up to that game was about the Spaniard's impressive record in European competition, but he failed to navigate his side beyond the Ukrainian club.
That means that Champions League qualification will now have to be done the hard way. Heading into the final matchday, their meeting with third-placed Lazio is now essentially a straight shootout for a spot in the elite club competition.
In truth, it has not been the greatest send-off for Benitez, with that failure to beat Dnipro in either leg coming in the middle of a five match run which has seen the Partenopei claim just one win.
That sole success came against relegated Cesana nearly a fortnight ago, but otherwise it is a potentially disastrous set of results should they fail to limp over the line in Serie A.
However, should Napoli fall short this weekend by failing to pick up the win they need, then it will not be their league results this month that has cost them. Instead, their run of form between March and mid-April, in which time they picked up just two points from a possible 15, will ultimately be scrutinised.
It is not all bad news for the Naples outfit, as their fate is still technically in their own hands as they head into the final matchday of the campaign. But a failure to get beyond the qualifiers back in August will still stick firmly in the minds of supporters, who know that there could be further pain to follow in the coming days.
Recent form in Serie A: WLWDWL
Recent form (all competitions): WDDLWL
While Napoli may be reeling from a bad few weeks, things have not been all that great in Rome, either. It was not long ago that Lazio were on a high, having collected 30 points from a possible 33, which left them looking good for a place inside the top three.
Since then, just two wins in their last eight outings have followed. Most tellingly of all, the Biancocelesti have slipped up right at the vital time at the business end of the campaign.
It would be harsh to criticise Stefano Pioli's men for failing to beat Juventus in last week's Coppa Italia final, but after taking an early lead, and eventually forcing extra time, they will feel hugely disappointed not to have taken advantage of the minor chink in Juve's armour when it appeared.
There was also a cruel defeat to city rivals Roma on Monday evening, which came about in a cruel fashion shortly after they had dragged themselves level, leaving Lazio now needing a point from their final game.
Pioli admitted himself in the aftermath of the 2-1 reverse that his players had been left hugely disappointed - a psychological blow which the Eagles must quickly shake off in order to get the job done against Napoli.
Individual league matches certainly do not come much bigger than this one, which is estimated to be worth at least £30m to the winning side in UEFA prize money. While it never should have gone down to the wire, Lazio will need to find some of the spirit which helped them overcome the same opposition in the semi-final of the Italian Cup earlier this year.
The difference between winning and losing, in a day and age when the Champions League truly dominates the European game, really could not be much more stark.
Recent form in Serie A: DWDLWL
Recent form (all competitions): WDLWLL
That could mean Ivan Strinic coming back into the starting lineup for his 12th appearance since joining from Lazio's conqueror's Dnipro back in January.
As far as the visitors are concerned, Stefan Radu may be welcomed back into the fold. He found the net against Juventus in the recent cup final only to have been sidelined since, and this game may still be a little too soon for him to return.
Lucas Biglia is also considered a doubt, meanwhile, after leaving the field early against Roma. The defensive midfielder was replaced by Luis Pedro Cavanda in the Eternal derby, but he should be okay to feature from the off.
Napoli possible starting lineup:
Andujar, Strinic, Maggio, Ghoulam, Albiol, Callejon, Mertens, Lopez, Insigne, Gargano, Higuain
Lazio possible starting lineup:
Marchetti, Basta, De Vrij, Gentiletti, Lulic, Parolo, Biglia, Candreva, Mauri, Felipe Anderson, Klose
Head To Head
Napoli are unbeaten in their last five games against Lazio, with the most important of those recent wins being the 1-0 victory back in January.
That Gonzalo Higuain-inspired success could be the difference between Europa League and Champions League football next term, as it comes down to a games-against record in Italy, rather than goal difference.
The Azzurri have also gone five matches without defeat against Pioli's men at home which, combined with the fact that they have not lost at the Stadio San Paolo since January, stands them in strong stead heading into this crunch match.
However, no team has picked up more points on their travels in the second half of the campaign than Lazio, which means that something has to give in Naples this Sunday.
We say: Napoli 1-1 Lazio
Both teams wasted the chance to get the job done last time out. Napoli could not beat a Juventus side who had their eye elsewhere, while Lazio failed to make the most of playing two days later against rivals Roma, knowing exactly what result was needed. It sets up a truly fascinating tussle for a qualification place in next season's Champions League, which the Eagles will claim thanks to a score draw.