It took until the second half for the deadlock to be broken with the returning Vincent Kompany rising high to score his first goal since August 2015.
Manchester City manager Pep Guardiola misses the pressure related to training in the Bundesliga and LaLiga, though he adores English assistants.
"Vincent is a central defender he is very good with the ball".
But despite failing to live up to his billing in his first season at Manchester City, Guardiola claims there is a sense of calm in England that he hasn't experienced before. Of course in that moment we came back from Barcelona, had played a lot of games in that period and we were exhausted. That is why I am so glad for the fans we have because it is the first time in my life I have experienced that'. He has the quality to move quicker, to find passes in small spaces, to help us in set pieces, both offensive and defensive because he's a real defender.
That's right, the fleet-footed youngster, who has played as an attacker for his entire career, could be used in an orthodox role for Die Mannschaft but, speaking to Manchester Evening News, Sane is not exactly keen on the idea.
Everton and Manchester United are six points further back.
Since then Aguero has scored 10 goals in his last 10 appearances, taking his season's total to 28 and his overall City tally to 164.
Southampton could have levelled after 74 minutes when Maya Yoshida powered a header too close to Bravo, but four minutes later they were out of the game thanks to a brilliant City goal.
City play Arsenal in the FA Cup semi-final at Wembley next Sunday and Guardiola went out of his way to urge the club's fans to give them an edge.
Southampton had barely got out of their own half for the first 15 minutes, but out of nothing they created the best opportunity of the opening period only for Dusan Tadic to blaze over from 15 yards out.
He said: "The problem when we concede goals is not the goalkeeper - it's not Claudio, it's not Willy (Caballero), it's all the team".
There's a youthful theme to Tuesday's media round-up, with the newspapers carrying stories on Manchester City youngsters Leroy Sane and Gabriel Jesus.