Klüft's selection for Barcelona generated controversy at home because the team manager, Olympic champion high jumper Stefan Holm, had given her a wild card for the competition.
Klüft's first-round leap on Tuesday was a season best and a full 20 cm further than what she had previously achieved in the qualifiers.
"It feels like a victory, as though I have come out and won gold," said Klüft. "I thought I had had it after my third jump and almost did not dare look."
Klüft only qualified for the final because her second-best jump of 6.51m was 4cm further than Switzerland's Irene Pusterla.
Her jumps are far off from her personal best of 6.97m set in Tallinn six years ago. Klüft was forced to miss the 2009 World Athletic Championships last year in Berlin and the rest of the season due to a thigh injury, so these championships are a comeback of sorts for her.
In addition to her controversial selection for Barcelona, she has continued to receive criticism for walking away from her successful heptathlon career in 2008.
The 2004 Olympic champion chose not to defend her title in Beijing, choosing to concentrate on the long jump instead.
"I've got nothing to say to them [her detractors]," she said. "People can think what they want. We live in a free land. All I can say is that I am tired of defending myself."
She added, "I haven't committed a crime, I haven's cheated, I haven't done ill to anyone or betrayed my country. I am tired of defending myself for what I am. Now I'm in the European final, like it or not."
However, she is adamant about her determination to win gold in London in 2012.
"Barcelona is important for continuing my career," she said. "Now I know I am capable of jumping really far next year."
As to whether she will recover in time for the final, Klüft added, "I am used to seven events in two days. I think I'll manage two in two days. I've got more to give."