Tennis star Serena Williams has apologized for her shocking loss at the U.S. Open over the weekend.

Serena took on 19-year-old, Bianca Andreescu, who beat Serena, 6-3, 7-5. 

"I think this was the worst match I've played all tournament. I can definitely say I'm not really happy, but I have to take it one moment at a time. I honestly didn't play my best. It's inexcusable for me to play at that level," Serena said after the match.

"I was thinking, OK, Serena, you didn't miss a serve, you lost serve maybe twice in the whole tournament. And you didn't hit a first serve in today. How do I play at a level like this in a final?"

But Serena says she is not after records, she just wants to win.

"I'm not necessarily chasing a record, I'm just trying to win Grand Slams. I just am still here. I'm still doing what I can do."