Manuel Pellegrini's side recovered from a poor first-half showing to seal an ultimately impressive 4-1 victory and here are five things we learned.
A champion-like performance
Southampton fans will rightly point to the injury of Jay Rodriguez and the kind offside decision which allowed David Silva to set up Samir Nasri for Manchester City's crucial second goal, but they will equally accept that the Etihad juggernaut deserved this hard-fought, and slightly flattering, 4-1 win at the end of it all.
For large spells of the first half City were second best against the Saints. They had taken the lead in just the third minute having raced out the blocks slightly the quicker of the two, but Mauricio Pochettino's men brushed off Yaya Toure's opening goal to dictate the tempo and peg City back.
It simply wasn't supposed to be this way. Pellegrini and his side were approaching this clash hoping to lay down the gauntlet to Chelsea and Liverpool in the first match of the weekend and, certainly on the evidence from the majority of the first half, there was little to fear for the fellow chasing pack.
City, though, are no ordinary team, particularly when they can boast the mercurial talents of Yaya Toure, David Silva and Samir Nasri, who combined to put the hosts back in front after Rickie Lambert's leveller.
Another soon after from Edin Dzeko and a second-half strike from Stevan Jovetic made the scoreline a slightly lop-sided one given the inroads Southampton had made during the first half in attempting to become only the second side to win at the Etihad this season in the league.
Their plan was undone by City's quickfire double on the stroke of half-time but, make no mistake about it, City were under severe pressure at one point. Hell, the 2011-2012 champions even appeared fearful of what damage Southampton's vivacious frontline could do to their title hopes.
This was a win with the hallmarks belonging to a title-winning outfit. If City can show the grit and determination that saw them over the line against Southampton, they will fancy their chances against anyone in the run-in.
Captain Fantastic steers City home
When the chips were down, and Southampton's pressing game began to trouble City in behind, particularly out wide, one man stood out above the rest to ensure his side would not be breached.
He could do nothing about the penalty which hauled the Saints back on level terms, after Pablo Zabaleta's clumsy challenge, but made it his personal mission to make sure that was as far as Southampton would get towards inflicting defeat.
That man, of course, was Vincent Kompany. Above all, the Belgian was a leader in a backline which appeared increasingly vulnerable as the opening period progressed.
Kompany was unflinching, though, standing firm in the face of pressure from Lambert et al to deliver a performance full of character, determination and leadership when his side required him most.
Martin Demichelis looked lost on a number of occasions as he struggled to cope with the attacking movement around him but Kompany rescued him and his full-backs on more than one occasion.
A block on the marauding Luke Shaw, who had evaded the attentions of Zabaleta down the left flank, was particularly admirable and his constant gesticulating and barking of orders showed just how vital the skipper will be if City are to go on and lift a second Premier League title.
Dzeko still has a City future
The Bosnian has seemingly benefited from the fact Alvaro Negredo is the current City striker out of form, having failed to find the net since notching a brace at the back end of January in the Capital One Cup semi-final second leg at West Ham.
Ever since Dzeko's arrival at City, he has failed to fit the superstar mould seemingly demanded from the Etihad faithful, who yearn for the return of Sergio Agüero.
Dzeko, though, still has plenty to offer this City side despite some obvious shortcomings. He may not supply the pace and, more pertinently, work rate of Agüero but what he lacks in those areas of his game, he more than makes up for it in others.
His runs, for instance, were perfectly timed throughout the contest and provided persistent problems for the Southampton backline while his decision making in the final third was, invariably, intelligent.
He won the penalty that got his side on their way as early as the third minute. Having peeled away from the centre halves, Jose Fonte was forced to hang a trailing leg and bring down Dzeko, handing Toure the opportunity to score.
His next true contribution to the match provided goal number three, as he found himself lurking in the right place at the right time to head home Aleksandar Kolarov's teasing cross.
His miss in the second half did not paint him in the most positive of lights and it was particularly intriguing to see the City fanbase get behind Negredo - Dzeko's replacement - after the Spaniard had squandered two presentable opportunities in front of goal.
You felt the same reception would not be afforded to Dzeko but his endeavours must not be under-appreciated by City this summer, when it comes to addressing their star-studded squad.
Lallana is not a World Cup squad member, he's a World Cup starter
The debate, as Adam Lallana's stock continued to rapidly ascend, was whether or not the Saints' star ought to be considered for a World Cup spot.
When he provided the cross for Daniel Sturridge to stoop and head home against Denmark in an international friendly just last month, it suddenly sparked a fresh question mark regarding his involvement in Brazil this summer. Should Lallana be included Roy Hodgson's starting XI.
The academy graduate appeared to have bypassed the first hurdle of getting into the 23-man squad and fans, pundits and seemingly the England coaching staff had fast-tracked the late bloomer into the first team.
No mean feat for a man who has fallen and risen with the club down to League One and back to the top flight, where he has continued to shine.
Saints fans will tell you this is no one-season wonder from their talisman, having seen him rise slowly but steadily to international recognition.
Against City, Lallana ghosted "between the lines," as Pellegrini put it in his post-match press conference, and caused interminable problems to the City defence.
While he was eventually drowned out by the towering midfield presence of Toure and the dynamic Silva, Lallana proved yet again that there simply must be a starting berth for him in Hodgson's side.
Jovetic deserves City chance
The Montenegrin has endured a frustrating debut campaign in English football with a succession of injuries retrenching his efforts to vindicate the club's £22million purchase.
The former Fiorentina man has only been able to show his talent in small spurts since his arrival but will be eager to finish this season strongly to boost his chances of contributing more next season.
Judging by Saturday's evidence, it is well within his capabilities. Evidently frustrated by Kolarov's inability to spot his run and pick him out with a pass, he refused to let it get the better of him.
Instead, he continued to dart into space in the hope of something running his way. It finally did, as Jesus Navas' cross fell perfectly for him to slide into an empty net and offer yet another glimpse of the talent he has as yet been able to truly fulfill at Eastlands.