Guardiola was seen in animated conversation with Redmond after the game and the Spaniard defended his actions by saying that he told Southampton winger that he is a better player than trying to play defensive football and wasting time.
"It was a good night, I think all the supporters create some special moments tonight and in the last second we enjoyed the situation", the City boss told a new conference.
The Spaniard added: "I can not control myself". "I said to Nathan: 'You are a good player and you have to attack'".
"What Redmond said in his statement, I admire him as a player and thank him for his comments", he added. "If they don't believe me, I don't know what I am doing here".
Guardiola insisted that his aggression was as a result of Southampton's time-wasting.
Guardiola said he would "never judge the way opponents play against one of my teams".
"It's so complicated when teams defend with ten players". Sterling also struck twice in added time in August, hitting a victor at Bournemouth and an equaliser against Everton in the only match this season rampant City have not won.
"I want to make it absolutely clear Pep Guardiola did not say what the Sun is falsely claiming in this story", Redmond said.
Guardiola faces a tough selection issue for Sunday's visit of struggling with West Ham - with Vincent Kompany, Leroy Sane and Fernandinho all one booking away from a suspension that would rule them out of the Manchester derby a week later.
That followed a similar, injury-time victor at Bournemouth and a point-saving late equaliser with Everton, the only team to have avoided defeat against rampant City this season.