The heartbroken, longtime partner of Felix Baumgartner — the Austrian BASE jumper and skydiver who died while paragliding in Italy this week — has shared chilling footage of his final takeoff.

Mihaela Schwartzenberg shared the clip Friday night of Felix rising into the air … noting in a touching tribute alongside the video that she had no idea he was beginning the final flight of his “extraordinary” life.

She went on to remember being there for nearly every one of Felix’s takeoffs and landings — from skydiving and paragliding to helicopter flights and beyond. And when she wasn’t there, they had a “WLC code” — standing for “the Wifey Landing Call.” She added … “Never missed one. Except …this one.”

Miha thanked all who have reached out for their support and seemed to find comfort in the fact that Felix “is going home now, up there, where he was the happiest ever.”

Still — the sudden loss of Felix is ripping her apart, and she said she must now deal with the shock and pain she feels.

As we reported, the record-setting extreme sportster, nicknamed “Fearless Felix,” died this week after he reportedly became ill and lost control of his aircraft.

He crashed near a hotel swimming pool in the town of Porto Sant’Elpidio, and had reportedly lost consciousness by the time of impact.

He was best known for his high-altitude jump from the stratosphere all the way back down to earth in 2012. He notably broke the sound barrier during his descent.