The 163rd Serie A meeting between these fierce rivals opened in an atmosphere as hot as the temperature in the Italian capital.
In an opening quarter-hour with some heavy challenges and very little by way of attacking impetus, it was former Roma man Pedro who had the first chance, firing over from the edge of the box before teeing up Nuno Tavares to finish similarly.
Roma were struggling to get anything going, and after Mile Svilar tipped Mattia Zaccagni’s effort over, Andrea Romagnoli powered a header just over from the resulting corner.
However, it was the Curva Sud that erupted in celebration after 38 minutes as the Giallorossi took the lead against the run of play.
Devyne Rensch robbed Tavares in his own box, allowing Matías Soulé to pick out Lorenzo Pellegrini for a clinical first-time finish into the bottom corner.
Gasperini’s men now had the momentum and came close to doubling their lead in first-half stoppage time, when Angeliño’s cross was flicked on by Evan Ferguson, only for Ivan Provedel to react quickest and stop Rensch from ghosting in at the back post.
Roma picked up where they left off after the break, attacking towards their raucous supporters. Angeliño met a cross at the back post but Provedel tipped his half-volley into the side netting.
Maurizio Sarri’s men then had a golden chance to level 10 minutes after the restart when half-time sub Danilo Cataldi sent Boulaye Dia streaking clear, but the Senegal international lost all composure with only Svilar to beat.
As the game ticked past the hour mark, Roma found themselves under increasing pressure as the Curva Nord roared on the Biancocelesti.
Lazio’s newfound momentum almost yielded an equaliser just inside the last quarter-hour, when Valentín Castellanos curled wide from just inside the box with an effort that looked to have taken a crucial nick off the boot of Gianluca Mancini, though only a goal kick was given.
That momentum for the ‘home’ side was dealt a hammer blow on 85 minutes when first-half sub Reda Belahyane was given a straight red card for raking his studs down the calf of Manu Koné.
Despite this, Svilar was called into a late save from Castellanos while Cataldi was already wheeling away in celebration before his curling effort struck the joint of post and bar.
Ultimately though, Roma hung on for a third win in four battles against their capital foes as Matteo Guendouzi was shown a red card after full time for overstepping in his frustrations.
Flashscore Man of the Match: Evan Ndicka (AS Roma)