Chelsea beat Real Madrid 2-0 at Stamford bridge, 3-1 on aggregate as they progressed to the finals.
The blues now set up an all-English tie with Manchester City coming May 29 in Istanbul.
Hazard was spotted laughing happily with some of his former teammates, Edouard Mendy and Kurt Zouma, after the final whistle.
Hazard's gesture drew criticism from Real Madrid supporters and Spanish media, with some fans even calling for him to be sold immediately.
But Hazard in his social said it was not his "intention to offend the Real Madrid fans".
"I am sorry. I have read lots of opinions about me today and it was not my intention to offend the Real Madrid fans.
"It has always been my dream to play for Real Madrid and I came here to win.
"The season is not over and together we must battle for La Liga! Hala Madrid!"
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