Lionel Messi took his tally to the season to an astonishing 52 goals with both for Barca, including a sublime second three minutes from time at the Bernabeu.
Real were reduced to 10 men in the 61st minute of a bad-tempered and at times ugly encounter as Pepe saw red following his late challenge on Dani Alves, with Jose Mourinho sent to the stands for his reaction to the decision.
Mourinho later launched a scathing attack on referee Wolfgang Stark and claimed that there was a conspiracy to favour the Catalan club.
Unlike in the build-up to the semi-final, when he responded to the Portuguese's pre-match pressure, Guardiola remained measured with his side closing in on the May 28 final at Wembley.
"We are one step away from the final but we are not at Wembley yet," he said.
"We respect Real Madrid a lot and we know they are capable of anything so we won't underestimate them.
"A team that has nine European Cups never gives up, I'm convinced of that.
"We played a very good game. We controlled their counterattacks and their aerial game which is very dangerous."
Messi is now the third highest scorer in Barcelona's history with only Cesar Rodriguez (235) and Laszlo Kubala (196) ahead of his tally of 178.
"At 23 he's the third leading scorer in club history. That's incredible," Guardiola added.