The manager is on track to lift his sixth major honour as City manager and he’ll be confident that his men can complete the job as they take a two-goal advantage back to the Etihad for the second leg of the semi-final.
City goalkeeper Claudio Bravo started his fourth-successive match but the real surprise was Guardiola, who made eight changes from the FA Cup win over Port Vale, opting not to go with a recognised striker as both Sergio Aguero and Gabriel Jesus were named on the bench.
Raheem Sterling was tasked with leading the line with Riyad Mahrez and Bernardo Silva either side of him, while Nicolas Otamendi returned after three matches out with injury to partner Fernandinho in defence.
They went into half-time with three goals after an excellent early performance, Silva opening the scoring with a top-corner thunderbolt past David De Gea.
He then played Riyad Mahrez through for the second goal, and the third came when Kevin De Bruyne’s strike – saved by De Gea – ricocheted back in off Andrea Pereira.
City could have even been four or five ahead before half-time, missing chances, before Marcus Rashford got United back into the game – and the tie – on the break in the second half.
Guardiola praised his team’s performance but says that Ole Gunnar Solskjaer’s Red Devils are capable of staging a comeback in the second leg.
“An outstanding goal from Bernardo and after we play really good,” the City boss told Sky Sports after the game.
“A lot of passes, arriving from behind. In the second half, they changed their shape – a diamond, 4-4-2 – we struggled a little bit more to keep the ball. But yeah, good result.
“It’s not over because it’s United and we’ve seen how many times – last season, a good example against PSG in the Champions League – so they’re able to score goals and get a good result.
“But hopefully with our fans, we can make a good game and reach the final again.”