Sofia Kenin full of emotion during Australia Open final

Even before she took out the Australian Open title, American Sofia Kenin was full of emotion in the middle of her match.

Kenin pulled off a stunning comeback to claim the title when she defeated Garbine Muguruza, 4-6 6-2 6-2.

When scores were tied 2-2 in the deciding set, the world No.15 stunned fans by notching 20 of the last 29 points to come out victorious.

But before her match even ended, tennis greats Sam Smith and Jim Courier were left shocked in the commentary box when they saw the American star fighting to hold back tears mid-match.

Shortly after finding her groove and claiming the second set, Kenin was full of emotions, stuck battling an opponent and trying to remain focused.

"Kenin's fighting off tears right now," Courier said.

"She's fighting on two fronts now. She's not just fighting Muguruza, she's fighting herself."

Smith revealed the 21-year-old was seen looking emotional all week, reduced to tears in the locker rooms before and after her matches.

"I heard today's she's been very emotional this whole week, she's been a bit teary in the locker rooms before and after matches," Sam Smith said

"She's taking deep, deep breaths, trying contain herself and control it," Courier added.