A stunning strike from Aleksander Kolarov earned Lazio a barely-deserved point, but Tommaso Rocchi suffered a potentially serious injury.
These two sides impressed last term to overcome Calciopoli penalties, but have stuttered somewhat when starting from scratch. The Amaranto were without a win under top flight debutant Massimo Ficcadenti, while Delio Rossi's men only broke their duck in the 3-1 midweek victory over Cagliari.
With the risk of being distracted by the upcoming Champions League clash with Real Madrid, Lazio were without the injured Mobido Diakhite, Fabio Firmani and Sebastiano Siviglia.
Ciccio Cozza marked his first start of the campaign with a well-taken goal. Cascione put the ball back into the box and Nicola Amoruso carried it on for Cozza's precise right-foot angled drive.
Gaby Mudingayi fired wide from distance, but Lazio only really started to threaten just before half-time, when Christian Manfredini failed to slide in Tommaso Rocchi's cross.
Lazio were playing very badly at the Stadio Granillo and Reggina nearly made it 2-0 when Barreto's shot took a deflection off Cozza to loop into the air and Muslera palmed it on to the bar.
Modesto really should have scored soon after, but he cut back to avoid a defender and fired wide of the near post with his weaker right foot.
Lazio created a goal out of nothing to draw level, as Aleksander Kolarov unleashed a left-foot absolute screamer from over 30 metres that smashed through the Reggina defence and past Campagnolo's outstretched hand. It was a shot of rare force.
There was bad news for Lazio, though, as Rocchi went off with a suspected sprained ankle that could rule him out of the Champions League match with Real Madrid.
Francesco Modesto was sent off in stoppages for dissent.