Maurizio Sarri’s men had conceded the first goal in four of their previous six Serie A outings, and the signs were ominous in the early stages, as Inter dominated the ball.
Although they were in control, the Nerazzurri seldom threatened Ivan Provedel in the Lazio goal, as the Italian shot-stopper retained his place over Luis Maximiano who had completed his suspension following a red card on debut.
The hosts grew in confidence, with the lack of threat on their own goal seemingly providing them the initiative to attack.
Ciro Immobile had two good chances to break the deadlock, with his first effort drifting wide before his second was palmed clear by Samir Handanovic.
Simone Inzaghi looked increasingly flustered on the sidelines and for good reason, as Lazio took the lead before the break. Sergej Milinkovic-Savic floated a delicious cross into the box, picking out Felipe Anderson who had found space between Alessandro Bastoni and Federico Dimarco, allowing the Brazilian to nod home.
Inter would need to respond after the break, and Inzaghi didn’t have to wait long as his side equalised within six minutes of the restart.
The hosts failed to deal with Dimarco’s delivery into the box, and Denzel Dumfries won the second ball, flicking the ball towards Lautaro Martínez to prod home.
Inter were in the ascendancy, and Dumfries nearly completed the comeback moments later with a close-range header at the back post, but Provedel was equal to it.
Sarri turned to his bench, introducing Spanish duo Luis Alberto and Pedro into the fray. The changes provided immediate impetus to the Lazio attack, and the pair combined for a truly spectacular goal to restore the lead.
Pedro laid the ball to Alberto on the edge of the box, and the playmaker unleashed a first-time howitzer, flying into the top corner, leaving Handanovic rooted to the spot.
Inter failed to apply pressure in their pursuit of a second leveller, and Lazio capitalised to double the advantage and seal all three points. Pedro, so influential since coming on, cut inside Stefan de Vrij and curled into the far corner.
Victory means the Eagles have won their opening two home league games of a Serie A season for the first time in seven years.
Flashscore Man of the Match: Sergej Milinkovic-Savic (Lazio)
