The 18-year-old striker came off the bench in the 64th minute of City's Capital One Cup tie against Sheffield Wednesday and netted the sixth goal in a 7-0 win.
"It is a dream to make my debut and also score," said the teenager
"I am very happy for this."
Pozo joined City two years ago from Real Madrid's academy and has earned the nickname 'Mini Messi' for his exploits.
His goalscoring has made him a star of City's youth teams and his first-team debut might have come earlier but for an ankle injury that ruled him out for most of last season.
But being told he has been compared to Barcelona superstar Messi drew a wide-eyed look from Pozo, who said: "This is crazy
Messi is the best player in the world and I have only played one game for the first team."
City boss Manuel Pellegrini revealed before the match against Wednesday that he was considering giving Pozo his chance, with Sergio Aguero, David Silva, Samir Nasri and Stevan Jovetic all struggling to overcome niggles.
Pozo certainly took his opportunity and will now hope to be given an opportunity in the Premier League.
He said: "Last year was very difficult because I played only five or six games before my injury
This season I'm working very hard
I know I am an Under-21 player but I have an opportunity and I'll try to do my best.
"I have been working with the first team for two weeks
I didn't expect anything
I was just working, waiting for my opportunity."
Many clubs were chasing Pozo's signature and Real were reluctant to let the teenager leave.
He has no regrets, and said: " Some people asked why I moved from Real Madrid to here but it is football
"I took my decision to come here and I think it is the right decision because I made my debut
I am very happy
"At Real Madrid it is very difficult because they sign the best players every summer
Also here it is difficult
But I think Manuel gives trust to the young players and he makes the young players feel closer to the first team
"I think City has very good plans for the future."
Those plans could yet include two Pozos on the pitch, with the striker's younger brother Iker also on the books.
Pozo thinks Iker has even more promise, saying: " My brother plays for the Under-14s
He is very good
He plays midfield
I think he is a very quality player."
Pozo was the only new face in a very strong City line-up and Pellegrini believes the Spanish youngster can be a real asset
"Pozo is a really good prospect for us, he's a player we believe in a lot," said the City boss
"Last season he was unlucky to have an injury in his ankle and it was a long time he was trying to recover
But he has shown a great level presently
I'm sure he will continue in the squad."
Frank Lampard and Edin Dzeko both scored two goals each with Jesus Navas grabbing probably the pick of the bunch and Yaya Toure netting from the penalty spot
City also hit the woodwork twice, through Eliaquim Mangala and James Milner, with the latter unlucky to miss out on man-of-the-match honours to Lampard
Milner was also the pick of the City team in last weekend's draw against Chelsea and is showing Pellegrini he deserves more than just a supporting role
"I'm not impressed because I know what James Milner can do," said the Chilean
"I think he's a player that always works 100 per cent every day, whether he's in the starting XI or not
"He's a great professional
Maybe in the last year he didn't play as much as he wanted to because the level of Nasri and Navas was really important also but now he's demonstrating every game that he plays what he can give to our team
"I am very happy for him."
Source : PA