City required a 90th-minute winner from substitute Sergio Agüero to gain the upper hand, after Kevin De Bruyne had cancelled out Bobby Reid’s opener from the penalty spot for the visitors.
The Robins provided a stern test for Guardiola’s side, with more of the same expected next Wednesday at Ashton Gate.
“All my credit to Bristol, you cannot knock four teams out of the Premier League without important players,” Guardiola said. “They were nice to watch. We were not going to finish qualification to the final today. That is at Bristol. It will be tough.
“Congratulations to them. They came here to try to play. [Marlon] Pack is a good player. The strikers have good mobility and courage to play. The game was really good for both sides - for the fans of both sides.
“Both teams tried to play, arrived and created chances. They are at the top in the Championship and I have a lot of respect for what they have done.”
The manager was impressed with his side’s reaction to conceding first, when Reid converted from 12 yards just before half time.
“In that moment, those games are more dangerous,” he said. “It’s so complicated. Semi-finals are always tough. At 1-0 we knew how to react. We had a chance with [Raheem] Sterling before the second half.
“I don’t know what will happen but I have a lot of respect because with this amazing schedule, they do everything they can. Every game they do absolutely everything they have. City fans here and around the world should be so proud of everything they’ve done, staying there.”
Raheem Sterling and Bernardo Silva were both used in the false nine position during the game, and Guardiola has faith in the duo to operate in the role with Gabriel Jesus sidelined with injury.
“They can play in that position,” he explained. “Bernardo has played it many times, Raz [Raheem Sterling] has played as a second striker when we have five at the back. They can play there. They don’t have the same natural feeling for the goal like Sergio or Gabriel, that is natural, but we are having to try with all the games we are playing. We have to rotate.”
Agüero came on to score his 19th goal of the season in all competitions, and Guardiola was keen to point out the need to protect his only fit striker.
“Sergio has had a lot of games. Gabriel is not a fit. We have to protect him [Agüero] a little bit, now he is on fire, scoring goals. Always he has been scoring goals. He has quality.”
City’s comeback marked a fifth game in which the Blues have overturned a deficit to claim victory, and Guardiola believes that such a mentality is key in finding success.
“Without that spirit, you can’t win trophies in any competition in the world,” he said. “It is easy in good moments to handle situations. In bad moments, it’s about how you handle situations. That’s why we’ve succeeded in those situations.”
