WATCH: Stephens pumped up over US Open victory

NEW YORK—Defending champion Sloane Stephens overcame a huge hurdle on Friday in Victoria Azarenka, 6-3, 6-4 to reach the fourth round.

Azarenka is a two-time Grand Slam champion and a formidable foe certainly capable of producing an upset. Judging by Stephens' pumped up reaction to that epic match point, she knew this was a great win.

"Very happy to be through," she said. "Obviously little rocky in the second set. I started off well and I played a solid match. So I was happy with that. The fight was good throughout. Really pleased."

Azarenka will have to swallow this loss and move forward with hopes of playing better at the "crunch" or crucial points.

"I think it comes from just preparation confidence," she said. "I really need a full offseason to train hard, to really train hard. I haven't had that in a long time. Maybe that's what needs to be added for those 1, 2 percent."

Azarenka had won their first three career meetings in straight sets before Stephens turned it around and has now tied it for 3-all. She takes on No. 15 seed Elise Mertens on Saturday for a quarterfinal berth.

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