It was an awful start for the visitors, who conceded early through Kyle Walker-Peters' first Premier League goal.
Manchester City quickly got on top of things, but it took until well into the second-half for the equalising goal to come - thanks to Aymeric Laporte.
Claims for a penalty and then a red card in favour of Pep Guardiola's side were dismissed by VAR, and the visitors couldn't quite find the second goal despite a number of chances including Kevin De Bruyne hitting the post.
Here's how City Xtra rated the players from a disappointing result for the Premier League leaders at St. Mary's:
Ederson - 6
The Brazilian was bailed out twice by the offside flag in the first half, and flapped at a header in the second. He can't be blamed for the opening goal, though.
Kyle Walker - 6
Overlapped far more than usual, presumably under Guardiola's instructions, but nothing ultimately came of it. You wonder why a man with Walker's immense pace doesn't attack like that more often.
Ruben Dias - 6
After the goal, the 24-year-old was vocal and largely untested. Southampton mostly tried to attack down the other side of the pitch - and who wouldn't when the alternative is Walker and Dias?
Aymeric Laporte - 7
Equalised for City, having become a real goal threat this season. The Spaniard wasn't at his best defensively prior to that.
Joao Cancelo - 6
Cancelo had some great moments, particularly a big tackle to prevent a counter-attack in the first-half. Looked like making things happen, but he might need to stop shooting over from range so much.
Rodri - 6
Not at his usual rock-solid self. I'd put that partly down to Southampton's well-drilled pressing and partly down to the absence of the crucial Ilkay Gundogan. He grew into the game, though.
Bernardo Silva - 6
Not at the levels of the first-half of the season, but still by no means bad on his 22nd consecutive Premier League start.
Kevin De Bruyne - 7 (MOTM)
The Belgian put in a brilliant cross for Laporte for the equaliser, forcing me to quickly delete my paragraph about how it wasn't De Bruyne's best game. He was a live wire from that moment on and hit the post with a sensational effort soon afterwards.
Raheem Sterling - 6
He really should have scored in the first-half but seemed surprised that the ball had run through to him. His worst game in ages, if I'm honest.
Jack Grealish - 6
The summer signing wasn't the only culprit today, but it was another game with no end product for Grealish, even though his talent is plain to see.
Phil Foden - 6
As with the whole front five, it didn't really come off for the 21-year-old today. Created a great chance for Sterling in the first-half and tested Forster with a volleyed effort following the interval.
Substitutes:
Gabriel Jesus - 6
Lively when he came on, getting physical with the defenders, but gave it away a few times later on.
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