Phil Foden, Gabriel Jesus and Ferran Torres in the final 10 minutes to secure a 3-1 win and avoid embarrassment.

Alfie May's second-half opener had put Cheltenham on the brink of one of the competition's biggest upsets.

The League Two side matched the six-time winners and City struggled for a breakthrough before eventually booking a fifth-round trip to Swansea.

Guardiola said: "We learned to suffer and at the end the quality made the difference. We won the game and we are happy to win this game in this type of competition.

"We knew how tough it would be and the response from the players was magnificent.

"The chances we had a 0-0 were so clear and if we scored it would have be very different.

"They had a fantastic team, what they do they do really well. They defended well, May is an exceptional player..

"In the FA Cup this is why it's nice, everyone can beat everyone. I don't have any regret over how we were behaving and the way we played. We scored three magnificent goals.

"We reacted so well, in this competition it's not the first time a Premier League team has suffered. We suffered well."

The Robins grabbed a shock lead when the visitors failed to deal with a long throw and May stole in ahead of Benjamin Mendy to score from close range.

Foden - City's best player - volleyed in Joao Cancelo's cross with nine minutes left before Jesus and Torres wrapped up the win.

Guardiola added: "Phil is playing really well and in the right moment he scored a goal. In the bad moments, when we were losing, he brought his personality to the game. Phil has to be Phil, not be Kevin De Bruyne."

Cheltenham are chasing promotion in Sky Bet League Two and sat 72 places below City.

Boss Michael Duff said: "I thought it was an incredible performance, I'm really proud of the players. Maybe we have stepped out of the racecourse's shadow for five minutes.

"There's a tinge of disappointment but the lads will get unbelievable attention so I told them to enjoy the moment but to turn up on Monday ready to go to work because we have Oldham at home (on Tuesday)."

Australian Associated Press