On the back foot for much of the match, the Rome club took the lead early on through Milinkovic-Savic's header. Inter may have dominated possession but perhaps would have lost by a greater margin were it not for some fine saves from Samir Handanovic.
Inter, still missing injured striker Mauro Icardi, squandered a great chance to race into an early lead, with Thomas Strakosha tamely punching a corner straight to Milan Skriniar, who could not keep his effort under the crossbar, sparing the Lazio keeper’s blushes.
And the Slovakian’s miss proved costly, with Lucas Alberto bending a lovely ball to the far post straight to Milinkovic-Savic, who was there to head home what proved to be the winner from close range.
Ivan Perisic twice looked a threat down the left but while Inter dominated play, it was Lazio who came closest to registering a second goal before half-time, with Luis Alberto’s free-kick met by Bastos only for Handanovic to get down well to make a superb save.
Luis Alberto was at the heart of all of Lazio’s positive play and almost scored himself with a bending effort which forced another impressive save from Handanovic.
Inter upped the ante immediately after the break, Perisic forcing an early save from Strakosha and Matteo Politano twice driving over.
At the other end, Handanovic had to make yet another impressive save, scampering off his line to thwart an effort from Felipe Caicedo and throwing himself at the feet of Ciro Immobile to block the rebound before making another save from the 29-year-old striker.
Substitute Radja Nainggolan stung the palms of Strakosha late on and Bastos almost headed into his own net but Inter were unable to conjure up a late leveller.
What does it mean? Lazio firmly in the top-four hunt
The race for the final Champions League spot in Serie A is now a fascinating one. Lazio are up to fifth and have a further game in hand to come. This victory moved them within three points of fourth-placed AC Milan and they are five behind Inter in third.
Luis Alberto pulls the strings
While Lazio defended manfully as a unit, there can be little doubt that the key to victory was their Spanish playmaker Luis Alberto. The 26-year-old set up the only goal of the game with a wonderful floated cross and was twice more involved in moves that threatened the Inter goal, setting up Bastos and forcing a save himself from Handanovic.
Skriniar left with regret
Inter’s attackers must carry the can for not creating more with their possession, though the entire complexion of the match would have been changed had Skriniar not squandered an easy opportunity to put the hosts ahead. He was also sluggish at the back, most notably when Caicedo barged through him to force Handanovic into another save.
Key Opta Facts
- Lazio have won a Serie A game against Inter for the first time since May 2016.
- Inter have failed to score in successive Serie A home meetings against Lazio (0-0 last term) for the first time since 1995.
- Lazio have won five of their last seven Serie A matches (D1 L1), as many as they had in their previous 15.
- They have also found the net in 17 successive Serie A games for the first time since December 2017.
- Inter have failed to win each of the nine Serie A games in which they have been trailing this season (D1 L8).
- Only against Parma (28) have Inter attempted more shots in a single Serie A game this season without finding the net than against Lazio (18).
- Luis Alberto has been directly involved in four goals in his last two Serie A games (two goals, two assists), as many as in his previous 20.