"It's fantastic," he said.
"Cardiff put us under a lot of pressure and we had to deal with difficult situations. My defence was fantastic." Redknapp, though, admits it was a nervous finish to the game as Dave Jones' Cardiff side battled in vain to find an equaliser.
"Very agonising," Redknapp continued when asked about the closing stages. "We weren't getting hold of the ball.
"We were 1-0 up, but they were threatening and credit to Dave and his team."
However, Redknapp was delighted to see hero Kanu - who was also the match winner in the semi-finals against West Brom - net Pompey's goal.
"He had a great chance just before, but I'm delighted for the big man," Redknapp added. "He scored in the semis and he has come back and scored again today."
The victory also means that Pompey will participate in next season's Uefa Cup and Redknapp, who has been rumoured to be heading for the Fratton Park exit in the summer, insists he is looking forward to competing in Europe.
"It's fantastic. I'm looking forward to it (the Uefa Cup)," Redknapp concluded.