There is more than pride at stake in the second Rome derby of the Serie A season as both capital clubs step up their late pursuit of a Champions League place.
With an all-Roman Coppa Italia final still a possibility should Roma overcome Inter Milan in a delayed semi-final second leg, which takes place almost three months after Lazio ousted Juventus inside a week, Monday's meeting might not be the final opportunity to claim bragging rights in the Eternal City.
But the league games are running out for Lazio to close a seven-point gap on third-placed AC Milan, with Roma a further three points behind following their shock defeat at Palermo and looking to remedy both matters at the Stadio Olimpico.
A fourth consecutive derby victory for Lazio - after they emerged 3-2 victors in November - could see them leapfrog Inter and possibly Fiorentina into fourth place, with both northern clubs facing tricky tests on Sunday afternoon.
The Nerazzurri are hoping to build on Wednesday night's 2-0 win at Sampdoria when mid-table Atalanta visit the San Siro, while Fiorentina host a Milan side with ambitions of finishing in the top two.
La Viola boss Vincenzo Montella said: "The Italian league is extremely difficult and there are always surprises around the corner.
"We must rediscover our best football and the best of Fiorentina. There are a lot of different games between now and the end of the season and our objective hasn't changed."
The trip to Florence is the first of three daunting fixtures for the Rossoneri, with second-placed Napoli and league leaders Juventus next on the agenda.
Milan boss Massimiliano Allegri said: "The team is improving before we go into three tough matches with a good lead over fourth place. All that counts for Milan is continuing down this path."
The top two both face struggling sides as Pescara head to the Juventus Stadium six points shy of safety and without a win in 11 games, while Napoli welcome 17th-placed Genoa, who are just one point clear of Siena.
The Bianconeri host an improving Parma side at the Stadio Artemio Franchi, with 19th-placed Palermo buoyed by their surprise 2-0 win over Roma and hoping to close a three-point gap on Genoa with victory at Sampdoria.
Elsewhere, ambitious Catania host Cagliari, who announced their decision to leave the Stadio Is Arenas this week, with Chievo nine points clear of danger as they travel to Udinese.
Torino surrendered their 3-2 lead on Napoli to lose 5-3 last weekend and so a better outcome will be required at Bologna's Renato Dall'Ara on Saturday evening.