Lazio mounted a superb second-half comeback at the Olympic Stadium to beat Inter Milan 2-1 and move above Antonio Conte's side into second place in Serie A on Sunday.
The visitors drew first blood when Ashley Young fired home his first Inter goal on the brink of halftime.
The victory moved Lazio into second on 56 points, one behind leaders Juventus and two ahead of Inter in third.
The result also saw the Roman club extend their club record unbeaten run in Serie A to 19 games as they ended Inter's own sequence of 16 games without a league defeat.
"We played a great game tonight," Lazio coach Simone Inzaghi told Sky Sport Italia.
"In the first half we were so convinced we would win that we allowed a few avoidable Inter counter-attacks.
"At halftime, I said that if we continued to play like that with a little more quality in the final ball, we could turn this around and win the game."
Lazio came agonisingly close to the lead after just nine minutes when Milinkovic-Savic's long-range shot cannoned back off the crossbar.
But it was Inter who broke the deadlock a minute before the interval, when Thomas Strakosha parried an Antonio Candreva shot into the path of Young, who fired a volley off the ground and into the roof of the net.
The hosts mustered a rapid response in the second half when Immobile was bundled over from behind by former Lazio defender Stefan De Vrij, and the Italy striker dispatched the resulting penalty to take his tally for the season to 26 league goals.
Lazio took the lead when Marcelo Brozovic's goal-line clearance from an Adam Marusic shot fell into the path of Milinkovic-Savic, who found a pocket of space and guided a composed finish into the bottom corner.
"I thought it was a very balanced game, neither team dominated the other," said Inter coach Conte.
"It was decided by two goals that in my view were entirely avoidable."