The Brazilian striker netted in both encounters - at the Bernabeu and the Etihad Stadium - and created an assist, as City sailed into the quarter-finals with a memorable triumph over the 13-time competition winners.
Gabriel Jesus played a crucial role in City's home victory, working tirelessly to harry and hassle Raphael Varane into two mistakes before setting up Raheem Sterling for the opener and then clipping home the winner on the night.
Guardiola was full of praise for his hard-working forward, deeming him the man of the tie.
"This competition will punish you - but Gabriel make his contribution to this," he said.
"He is the best guy at making these kind of actions. Gabriel was man of these two games.
"He scored in Madrid and then today made an assist and scored a goal.
"Gabriel always helps with more than goals but for a striker it’s important to score.
"For big players, it's important to show it on the biggest stage. He has done it twice and he made a big step to say: ‘Here I am, I can win games myself."
Hear what Pep had to say about the triumph in the video above...