But less than a minute after record summer signing Gonzalo Higuain came off the bench to replace Mario Mandzukic midway through the second period, Germany midfielder Khedira was set up by Paulo Dybala and beat Federico Marchetti at the ‘keeper’s far post.
It was enough to see Juve go provisional top ahead of the remaining fixtures on Sunday, but after a busy summer transfer period Massimiliano Allegri was quick to calm fans’ expectations.
“Given the heat in Rome and the fact Lazio are a well organised side we were never going to dominate this game, although we were the better side by the end of the opening period,” said Allegri.
“But we had a much better second half: let’s say we’ve started better than we did last year.”
Juventus had a disastrous start to last season before fighting back into contention around the new year. But having signed Napoli’s most important asset in Higuain last month, the champions now have no excuses as they go in search of a record sixth straight title.
With Higuain still lacking fitness, the Argentine striker started on the bench for the second consecutive week, just as Allegri had indicated on Friday.
After a quiet first half Juventus began to build momentum, with shots from Mario Mandzukic, Paulo Dybala and Khedira missing the target.
Higuain came off the bench to replace Mandzukic with 25 minutes to play, but only after Immobile’s chip flew across the Juve goalmouth, with no takers.
The effect was immediate, but unlike last week — when Higuain came off the bench to hit the winner with his maiden goal for his new club — the spotlight fell on Khedira.
The German held off his marker to collect Dybala’s smart chip, turned inside and beat Marchetti at his far post with a crisp, angled shot.
Higuain celebrated like he had scored himself, but with later attempts that came to nothing the 28-year-old showed he is still lacking the zip that helped him to a record 36 goals in Serie A for Napoli last season.
Napoli made amends for Higuain’s shock departure by signing Arkadiusz Milik, and the Poland striker made sure fans got to know his name by hitting a first-half brace in a thrilling 4-2 win at the San Paolo.
Napoli had amends to make after a 2-2 draw at promoted Pescara last week but Milik gave them a 2-0 lead by the 33rd minute after he tapped home a rebound then rose to beat Gianluigi Donnarumma with a glancing header.
Milan looked to have fought their way back when M’Baye Niang, with a fine individual effort from a tight angle, and Spanish striker Suso, with a spectacular curling shot, pulled the Rossoneri level on 55 minutes.
But Juraj Kucka saw red soon after for a needless challenge on Dries Mertens, his second bookable offence, and when Mertens saw Donnarumma save his angled drive with 16 minutes to play Callejon ran in to convert the rebound.
It went from bad to worse for Vincenzo Montella’s men as Niang saw red for a second bookable offence when he barged into Reina with two minutes on the clock.
In added-on time, Callejon should have scored his second but saw his goalbound shot pulled out of the net by the hand of defender Alessio Romagnoli, who was attributed the own goal.