Sloane Stephens suffered a collapse of epic proportions to crash out of the U.S. Open.

The struggling American won the first nine games and served for the match in both the second and third sets, only to fall to Clara Burel.

The Frenchwoman pulled out a stunning 0-6, 7-5, 7-5 win to send Stevens packing from Flushing Meadows.

It marks the third straight tournament Stephens dropped her opener after getting bounced in Washington and Toronto.

The 2017 US Open champ, Stephens dominated the first set and appeared in complete control under the lights at Arthur Ashe Stadium.

But after taking a 6-0, 3-0 lead, the wheels came off for her. Stephens dropped seven of the next nine and ended up having to play the third set.

After both players took a break before the third set, Stephens held serve and then broke to go up 2-0.

But in a set that had six breaks, Burel broke back to knot it at 2-all. 

Stephens broke to serve for the match at 5-4. But she got broken again to let Burel level at 5-all.

Stephens dropped the last two games — opening the final game with a catastrophic double fault — and was sent packing.

“I was a little bit nervous at the beginning. Sloane Stephens was making it (tough) for me,” Burel said in an on-court TV interview. “I just kept fighting. I found a way 

“I think that was the turning point when I tried to be more aggressive, I started to win more points…it started to pay off.”