David Silva! 4-1! Surely it's all over now!
If that gave Guardiola something to ponder at the interval, it required just three minutes of the second half for Silva to restore City's three-goal cushion.
Aguero, who turned 30 in the close-season, has now scored 14 times in his last eight Premier League games at City's Etihad Stadium.
The deadlock was eventually broken on 25 minutes as Ederson's long-ball found Aguero, who sent a cheeky lob into the back of the net from the edge of the box. "I've heard it could have been worse, that's always good news and I hope we can see that in a few days at least".
Jon Gorenc-Stankovic pulled one back before the break but it was to be a brief consolation as David Silva celebrated the attendance of his son by scoring in the youngster's presence.
Guardiola, meanwhile, has confirmed Kevin De Bruyne is likely to be sidelined for three three months and revealed the tear of lateral ligaments in his right knee was down to fatigue.
Five minutes later, Aguero had his third - and his 31st league game in which he has scored multiple goals.
The sparkling David Silva was replaced by Riyad Mahrez moments later as Pep Guardiola made his first change, and then Huddersfield defender Christoph Schindler was shown a yellow card for a hack on Jesus. It's part of the game, part of the amount of games and seasons, games and seasons (they play) and in the end the players fall down.
"Last season was a tough moment for his family but fortunately, the little boy fought a lot".
City are spoiled for midfield choice as Juergen Klopp, manager of rivals Liverpool, noted on Friday when he told Sky Sports how sorry he was about De Bruyne's misfortune. Next up for the Terriers is Cardiff, and Wagner will be looking for a morale-boosting result ahead of the winnable tie against the newly promoted side.
He added: "I don't know what's going to happen in the future, but we decided today to play with two strikers in Sergio and Gabriel and they connected really well".
Former Man City man Aaron Mooy will have a point to prove against his old side.