Guardiola’s second-placed side closed the gap on leaders Arsenal to just two points with their tense victory at the Etihad Stadium.
Nico O’Reilly put City ahead in the first half and restored the lead before half-time after Lewis Hall had equalised.
City weren’t at their best in the second half, but they held on to pile pressure on spluttering Arsenal, who travel to Tottenham for the north London derby on Sunday.
Guardiola knew it was essential to make Arsenal sweat.
“Massive. Newcastle is an incredible team, awesome in physicality and speed they have up front. Physicality in the middle. Really tough but the team was unbelievable,” he said.
“It’s coming in best part of the season. Every single game will be similar to today.“
After finishing without a trophy last season, City are back in the hunt for the seventh English title of Guardiola’s reign.
They will have a game in hand on Arsenal after this weekend and are guaranteed to win the title if they win their last 11 league matches.
Guardiola has embarked on an expensive overhaul of City’s squad in the last 12 months, shedding ageing stars like Kevin De Bruyne, Ederson and Kyle Walker and bringing in the likes of Marc Guehi, Antoine Semenyo and Rayan Cherki.
The Spaniard is well aware that his new generation largely lacks the experience of winning under the pressure of a title race, which made their gritty success against Newcastle even more meaningful.
“70 percent of the players have never been in that situation, and I don’t play. So we have to live it, they know that every game will be like this,” he said.
“Especially at home, with five home games left. Today was the best crowd of the year, it was unbelievable with our people, really proud to be manager of these incredible people and fans.
“Of course in terms of points it’s important, but we have to improve to have chance to compete until the end. Now we deserve three more days off. Then another battle in Leeds.“
Guardiola singled out O’Reilly for praise after the young England midfielder’s pair of clinical finishes showed he won’t be affected by the strain of chasing Arsenal.
“Nico give us in the middle that physicality that we need. He now plays in his position,” he said.
“He has always played that, he is so complete and so young. I am really pleased the academy produced these incredible players, Nico, Phil (Foden), Rico (Lewis).“
