1 Ferna effect
He's been sorely missed.
Fernandinho's return after a three-game absence with a thigh problem was a significant boost for City, and it didn't take long for him to show us just what we've been missing.
Energy, running power, dynamism, tackles, interceptions and blocks; the protection he offers the back four makes him indispensable.
But he is also a technically gifted player capable of launching attacks with his brilliant range of passing.
He's the complete holding-midfielder, and City are a better side with him in it.
READ: De Bruyne injury update
2Aguero hits Guardiola-era half-century
It was his ninth direct goal involvement (five goals, four assists) in nine matches against the Saints.
And perhaps more significantly, it was his 50th Premier League goal in 72 appearances since Guardiola took charge, a stat that underlines his remarkable consistency and offers further evidence of Pep’s management skills.
3 Silva service
David Silva delivered another fine display, once again demonstrating his vital importance to this side.
He remains our creative hub and one look at his stats from the game proves his influence. He scored the opener, created four clear chances (the same as the Southampton team combined) and completed 91 per cent of his passes.
It’s now 70 goals and 104 assists in 368 appearances for City. His 54 Premier League goals mean he is the second-highest Spanish scorer in the history of the competition.
It seems he’s getting better with age.
4 City show their mettle
When Southampton equalised after 37 minutes and then had a penalty shout moments later, it would have been easy for City to wilt under the pressure. After all, defeat at St. Mary’s would have seen our title hopes suffer a major blow.
But eight minutes later, we were ahead, before adding a third just before half-time to assert our dominance. The players had been severely tested but managed to regain control of the match and earn three vital points.
That is the kind of character this squad has shown time and again and will be needed if we are to overhaul Liverpool's lead in the table.
It’s a fact that has gone somewhat unnoticed: our first-choice midfield three of Fernandinho, David Silva and Kevin De Bruyne are yet to start a Premier League game together this season.
Hopefully, that will change soon. Guardiola said after the game De Bruyne's latest setback isn't serious, but he couldn't put a timescale on his return.
Wouldn't it be brilliant to have those three in tandem for Thursday's big one...