The defending champions were superb at Old Trafford, scoring three times in an utterly dominant opening 45 minutes and seeing out the game in a professional manner thereafter, despite Marcus Rashford’s late reply.
It was an emphatic response to last month’s 2-1 Premier League defeat at the hands of the same opponents, who that day profited from a slick counter-attacking display.
And though City were magnificent going forward this time around, Guardiola was pleased with the entire performance and, particularly how we prevented United from exposing us on the break.
“The first minutes were tight but then we had an outstanding goal and we played really good,” he said.
“We played a really good game with a lot of passes from behind.
“In the second half they changed their shape with the diamond, and we struggled to keep the ball a bit more, but it is a good result.
“We knew it was difficult to control Rashford as they are so fast and that was our target today. In the last game we could not control when we lost the ball and tonight we did it better.
“In general, it was an incredible performance and just a fantastic result for us. Tonight we can be more than satisfied to come here to Old Trafford and win.”
For all his joy, Guardiola was quick to point out the tie is far from over.
Bernardo Silva’s 20-yard rocket, Riyad Mahrez’s effort and Andreas Pereira’s own goal meant City were cruising at half-time, but Rashford’s strike gave United hope ahead of the second leg in three weeks’ time.
And whilst the City boss is hopeful the Etihad Stadium crowd can help his players complete the job, he is adamant we can take nothing for granted if we want to reach a third consecutive Carabao Cup final.
“It is not over as it's United and we saw last season, at PSG for example, what they can do,” he added.
“We have one more game and we'll see what happens.
“It’s a good result, but hopefully with our fans we can make a good game and reach the final again.”