The 24-year-old completed an improbable comeback on Saturday. (Getty)

One of the most improbable sports comeback stories was completed when 24-year-old Sloane Stephens won the US Open over friend and fellow American Madison Keys. Her first major title comes after nearly one year of recovering from a foot injury.

Of course, the world took notice and there were all kinds of congratulations and compliments.

Two years ago, Flavia Pennetta won the US Open before retiring, so she has an inkling of what this moment means for Stephens.

Maybe the most meaningful congratulations was a personal hug from new Hall-of-Famer Kim Clijsters who was a comeback queen and inspiration for Stephens.

The Tennis Channel reminded everyone of what Stephens was up to just this spring.

Throughout the tournament, Stephens has been lauded for her consistency, fight and composure.

Even the rest of the sports world was paying attention, particularily those who typically cover basketball and football.

The best congratulations of all came from Keys after match point. 

Now, this was a US Open to remember.